Vitamin D Intervention in Children With Sickle Cell Disease: A Pilot Randomized Controlled Trial
Phase: PHASE3
Conditions: Sickle Cell Disease
Sponsor: St. Justine's Hospital

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A VITAMIN D INTERVENTION IN CHILDREN WITH SICKLE CELL 
DISEASE: A PILOT RANDOMISED CONTROLLED TRIAL   
 
 
 
 
 
 
 
 
 
 
PRINCIPAL INVESTIGATORS :  
 
NATHALIE ALOS, MD 
CHU SAINTE-JUSTINE RESEARCH CENTER 
 
GENEVIÈVE MAILHOT, PH.D, Dt.P., RESEARCHER,  
CHU SAINTE-JUSTINE RESEARCH CENTER 
 
 
 
COLLABORATORS :  
 
 
YVES PASTORE, MD, CHU SAINTE-JUSTINE 
NANCY ROBITAILLE, MD, CHU SAINTE-JUSTINE 
SYLVIE LEMAY, PH.D, RN., CHU SAINTE-JUSTINE 
 
 
PASCALE GRÉGOIRE-PELCHAT, RESEARCH TRAINEE

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TABLE OF CONTENTS  
 
Introduction......................................................................................................... 3  
State of knowledge and preliminary data in support of this 
proposal…………………………………………………………………………….4 
Rationale……………………………………………………………………………5 
Hypothesis........................................................................................................... 6  
Research objectives.............................................................................................. 6  
Description of the population……………………………………………………..6 
Participants approach…………………………………………………………...…7 
Methodology…………......................................................................................... 7  
Statistical analysis…………………………………………………………………11 
Clinical significance…………………………………………………………...….12 
Ethical issues………. ........................................................................................ 12 
Research team……............................................................................................. 14  
Timeline ............................................................................................................. 16  
Budget………….. .............................................................................................. 16   
Knowledge translation……………………………………………………………16 
References……………………………………………………………………..…..17 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   

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INTRODUCTION  
 
Sickle cell disease (SCD) is an inherited blood disorder affecting predominantly individuals of 
African descent and caused by a mutation in the gene encoding the β-globin protein, thereby 
resulting in its abnormal structure and hence dysfunctional red blood cells. Ultimately, such 
alterations lead to multi-system vaso-occlusion, for which the most common clinical manifestation is 
recurrent painful episodes. Moreover, patients with SCD cope with other complications including 
poor bone health, chronic systemic inflammation and impaired cell-mediated immunity, for which 
vitamin D deficiency is known as a potential contributing or exacerbating factor.  
Vitamin D deficiency is particularly prevalent in children with SCD  
Vitamin D deficiency is now recognized as one of the most common nutritional conditions among 
individuals with SCD with prevalences ranging from 56 to 96.4%1. The high prevalence of vitamin D 
deficiency is attributed to several factors impeding vitamin D endogenous production, intake or 
metabolism. Indeed, most SCD patients are dark skinned, which limits their cutaneous synthesis of 
vitamin D. Lactose intolerance, highly prevalent in African Americans, as well as damage to the 
intestinal mucosa may reduce dietary intake of vitamin D and interfere with its absorption. Finally, 
comorbidities such as liver or renal impairment may affect the conversion of vitamin D to its 
circulating and bioactive form respectively.  
Since SCD patients have high nutritional demands due to the constant production of red blood cells, 
alterations in micronutrient intake, supply or metabolism are of concern. Furthermore, we showed 
that, despite three-monthly follow-ups, use of and compliance to vitamin D supplementation are 
particularly low in this population2. In light of these findings, it is reasonable to postulate that 
optimizing vitamin D nutrition of SCD children, using a dosage regimen that favours compliance, 
may prevent or lessen SCD-related complications. While the role of vitamin D deficiency as a 
contributing factor in SCD complications is not yet proven, vitamin D deficiency could be reliably 
and inexpensively treated, making it a prime intervention to potentially improve health outcomes 
among those with SCD.   
The overarching aim of this pilot randomised controlled trial (RCT) is to assess the feasibility of 
recruitment and intervention, and obtain pilot safety data of a single oral bolus of vitamin D3 to 
inform the design of a larger-scale RCT. Secondarily, we aim to: 1) observe if a single oral bolus of 
vitamin D3 effectively raises serum 25-hydroxyvitamin D (25OHD), the marker of vitamin D status, 
to levels considered sufficient for potential extra-skeletal benefits (≥75 nmol/L) in children with 
SCD; and 2) determine if this intervention is associated with improvements in outcomes clinically 
relevant to SCD children.  
 
 

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STATE OF KNOWLEDGE AND PRELIMINARY DATA IN SUPPORT OF THIS 
PROPOSAL  
 
A large proportion of SCD children followed up at Sainte-Justine University Hospital Center exhibit vitamin D 
deficiency/insufficiency   
We previously conducted a cross-sectional assessment of vitamin D status, intakes and compliance to 
supplementation in a cohort of children with SCD (n=116), representative of the population of SCD 
patients followed up at Sainte-Justine UHC (total population is 307)2. We measured 25OHD levels in 
summer and fall in order to capture, not only the contribution of dietary and supplemental vitamin D 
to vitamin D status, but also of sun exposure. With this approach, we portrayed more accurately the 
highest vitamin D status these individuals managed to get to. Nevertheless, despite a significant time 
spent outdoors in summer (108±58 min/day), two-third of children (66%) had suboptimal vitamin 
D status (<50 nmol/L) while 33% were deficient (<30 nmol/L), thereby confirming that vitamin D 
synthesis through sun exposure is limited in these children in our latitude during summer. The 
situation was even worse in fall whereby 77% and 55% of children were vitamin D insufficient (<50 
nmol/L) and deficient (<30 nmol/L) respectively. Regardless of season, only 6% of children had 
vitamin D sufficiency (≥75 nmol/L) with a maximum value of 99 nmol/L. Serum 25OHD levels did 
not vary according to genotypes (the most severe SS: 41.0±20.4 nmol/L; SC:  45.7±17.9 nmol/L; 
and β-thal: 40.4±15.9 nmol/L; p=0.767). Vitamin D intakes (353±234 IU) were below 
recommendations (600IU/day) in 72% of children and came mostly from foods (292±128 IU). 
Moreover, our data revealed that only 8 children (out of 46 questioned; 17%) took vitamin D 
supplement and only 50% of these children (n=4 out of 8) reported taking it at least 4 days a week. 
The high proportion of SCD children with impaired vitamin D status combined to the low 
proportion of subjects consuming supplements, their poor compliance, their northern geographical 
location and their limited ability to produce vitamin D from sunlight led us to propose an 
intervention strategy to overcome these issues.   
Vitamin D is important for SCD children   
Beyond its effects on bone, vitamin D deficiency has been linked to multiple health conditions 
including cardiovascular disease, inflammatory disorders, asthma, nephropathy, and chronic 
musculoskeletal pain, all of which are also complications of SCD. Our preliminary data revealed that 
SCD children with vitamin D deficiency (25OHD<30 nmol/L; n=36) had lower haematological 
values (total hemoglobin and erythrocyte counts) and higher level of the pro-resorptive parathyroid 
hormone (PTH) compared to those with 25OHD>30nmol/L (n=72)2. In support of our data, 
others have found pathological association between 25OHD levels and acute or chronic pain, 
markers of hemolysis as well as low bone mineral density3-6. Based on these findings, we postulate 
that an impaired vitamin D status contributes to multi-system functional impairments in SCD 
children, which in turn, leads to the onset or progression of SCD complications and deterioration of 
quality of life. These results provide a clinical rationale for the correction of vitamin D insufficiency 
in these children.    

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Very few vitamin D intervention studies have been conducted in SCD children     
Only six studies aimed at documenting the effects of vitamin D supplementation on vitamin D status 
and clinical outcomes (e.g. chronic pain, haematology and inflammation) in SCD children have been 
published thus far7-12, among which only one has reported the effects of a vitamin D bolus7. In the 
most well-designed study, Dougherty et al. randomized 44 African-Americans aged 5 to 20 years 
with (n=21) and without (n=23) SCS-SS to daily 4,000 or 7,000 IU vitamin D3 (no placebo) for a 
period of 12 weeks11. While 57% of children had suboptimal status (<50 nmol/L) at baseline, it 
decreased to 5% after 12 weeks of supplementation with a significant reduction in PTH levels, which 
may benefit bone health by attenuating bone resorption. Modest improvements in hematology and 
inflammatory outcomes were also reported but an adherence rate of 73% may have confounded the 
clinical effects of the intervention. Although 4000 to 7000 IU vitamin D3/day appears effective to 
correct suboptimal vitamin D status in this population, compliance remains an issue and an 
intervention strategy aimed at improving this aspect is warranted.   In their pilot study, Osunkwo et 
al. randomized 39 SCD children and adolescents (7-21 years) to a vitamin D3 bolus dosed according 
to weight (i.e. 240,000-600,000 IU) and given over 6 weeks (note: frequency of bolus administration 
is unclear) with monitoring extended to 6 months7. In addition, subjects received daily 200 IU 
vitamin D3 and there were no placebo group. Safety data were not provided but clinically, the 
authors found a notable reduction in the number of pain days and evidence of improved physical 
functioning with a rise in serum 25OHD with the peak effect occurring when serum 25OHD > 
75nmol/L. These effects were not influenced by baseline vitamin D status suggesting that vitamin D 
therapy may benefit all SCD patients, not only deficient patients. This study also highlights the need 
for pulsed dosing to achieve serum 25OHD>75nmol/L combined to a daily supplementation 
required to maintain and further increase the gain in serum 25OHD.  Finally, most intervention trials 
have been conducted among African-Americans or children of unspecified ethnicity while none has 
been specifically carried out in children of predominantly sub-Saharan African and Haitian origin, 
which represents 90% of our population (vs. 1% of African-Americans). In addition, vitamin D 
status of Canadian SCD children, a group characterized by limited sun exposure during winter, has 
been documented in only one study, along with other micronutrient deficiencies13. Our study will 
therefore advance the knowledge on the efficacy and safety of vitamin D among SCD children of 
ethnicities and geographical location that have been underrepresented in previous studies.  
 
RATIONALE 
 
The rationale for the proposed trial is summarized below:   
 
1. More than two-third of SCD children followed up at Sainte-Justine UHC are either vitamin D 
deficient or insufficient during summer and fall and may therefore clinically benefit from improving 
their vitamin D status.  
2. Given the low dietary and supplemental intakes of vitamin D of SCD children, their poor 
compliance to vitamin D supplementation, their compromised cutaneous synthesis of vitamin D, the 
presence of other potential contributing factors (e.g. impaired vitamin D metabolism, increased 

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nutritional demands, lactose intolerance) and the poor adherence to the CanHaem clinical practice 
guidelines14 regarding vitamin D, a vitamin D nutritional intervention is clinically and ethically 
desirable.   
3. The fact that conditions associated with vitamin D deficiency/insufficiency are similar to SCD-
related complications suggests that correcting vitamin D nutrition of these children may potentially 
result in clinical improvements and ultimately a better quality of life.  
4. Very few SCD children in our cohort had serum 25OHD levels > 75 nmol/L (i.e. 6%), the 
suggested target level for the extra-skeletal effects of vitamin D. Given that some clinical benefits 
have been demonstrated in SCD children when serum 25OHD exceeds 75 nmol/L, an effective 
intervention strategy aimed at normalizing vitamin D status while ensuring reasonable compliance is 
warranted.  
 
HYPOTHESIS 
 
 
We hypothesize that administration of a single oral bolus of 300,000 IU of vitamin D3 to children 
with SCD represents a safe, acceptable and clinically feasible regimen that will result in the 
attainment of vitamin D sufficiency (25OHD levels >75 nmol/L) in 80% of participants and in mild 
improvements in some clinical outcome measures after 3 months.  
 
RESEARCH OBJECTIVES 
 
   
 
Primary objectives:  
• To assess the feasibility of recruitment and intervention (vitamin D3 bolus)  
• To assess the acceptability of the intervention by patients and parents  
• To assess the safety of the vitamin D3 bolus (serum and urinary calcium levels, serum 25OHD)  
 
Secondary objectives:  
• To observe the mean change in total serum 25OHD from baseline to 3 months. At 3 months, a 
raise of the 25OHD level to 75nmol/L or more is expected.  
• To observe the effects of the vitamin D3 bolus intervention in improving growth (height, weight 
and BMI), haematological (fetal hemoglobin), inflammatory (TNF and IL-6), bone health (PTH, 
biochemical markers of bone formation and resorption, musculoskeletal pain) and quality of life.  
 
DESCRIPTION OF THE POPULATION 
The children who will participate in this study are the ones who are followed at the Sainte-Justine 
UHC SCD clinic. Inclusion criteria: Children aged 5 to 17 years regardless of SCD genotypes (e.g. 
HbSS, HbSC, HbS/β-thalassemia, others). We purposely choose to include all genotypes since our 
preliminary data showed that they did not differ much in terms of vitamin D status and should 
therefore all benefit from optimizing vitamin D nutrition. Exclusion criteria include: conditions or 

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use of medications known to interfere with calcium or vitamin D absorption or metabolism, known 
hypercalcemia, conditions characterized by a hypersensitivity to vitamin D (e.g. granulomatous 
disorders), patients clinically diagnosed with rickets or other conditions requiring vitamin D therapy, 
history or presence of urolithiasis, anticipated difficult follow up, patients already enrolled in other 
investigational studies, recent hospitalization for severe pain crisis or acute sickle complication in the 
past 2 weeks and unresolved pain issues. 
 
PARTICIPANTS APPROACH 
 
Children attending the Sainte-Justine UHC SCD clinic will be screened for enrollment by a research 
trainee. Eligible children and parents will be approached at their next follow up appointment at the 
clinic by the collaborating haematologists. The children and parents interested to participate in the 
study will then meet the research trainee for a more in depth description of the study and to answer 
any questions they could have. The consent form will be signed in the presence of the research 
trainee the same day or during the patient’s next appointment at the clinic. 
 
 
METHODOLOGY 
 
Design: We propose to carry out a pilot double-blind RCT in children aged 5-17 years followed up 
at the SCD clinic of Sainte-Justine UHC.    
Randomisation and allocation concealment: Using a computer-generated random list, children 
will be randomly allocated to placebo or intervention, using random permuted blocks. The Applied 
Clinical Research Unit of Sainte-Justine UHC will generate the randomisation scheme. Group 
allocation codes will be held in a secure location with a restricted access by the Central pharmacy 
(Sainte-Justine UHC). All participants and research personnel, including the nurse, research trainee 
and research team will be blinded to group assignment.   
Interventions: Experimental group: a single liquid bolus of 300,000 IU oral vitamin D3, which 
corresponds roughly to 3,333 IU/day; Control group: placebo identical in taste and appearance. The 
proposed dose of bolus vitamin D3 is based upon a previous report showing that 4,000 to 7,000 
IU/day administered to SCD children over 12 weeks was effective to correct vitamin D insufficiency 
in more than 95% of their cohort and led to some clinical improvements11.  
Co-interventions: In addition, all subjects will be provided with a 3-month prescription of vitamin 
D3 tablets (1,000 IU/tablet) to comply with the CanHaem guidelines14 and instructed to take 1 pill 
per day.  The research trainee will assess calcium intake and if deemed too low, participants will also 
receive a prescription for calcium supplements in order to ensure adequate daily calcium intake. The 
reason for such a co-intervention is to prevent symptoms of hypocalcemia in those who take 
supplemental vitamin D but have a low calcium intake.  

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Overall, participants in the experimental group will be taking 4,333 IU/day + dietary vitamin D 
intake, which falls within the range of 4000 to 7000 IU/day previously found to correct suboptimal 
status of SCD children11. Placebo group will be taking 1,000IU/day in addition to dietary vitamin D 
intake. Previously, the evaluation of dietary vitamin D intakes of a sample of children attending the 
SCD clinic at UHC Sainte-Justine (n = 46) revealed that the children took, on average, 292 +/- 128 
IU of vitamin D per day2. Therefore, by taking into account dietary vitamin D intakes similar to what 
we have previously found, the participants in the experimental group will take 4, 625 IU of vitamin 
D per day in total (supplement + dietary intakes) while participants in the placebo group will take 1, 
292 IU per day. 
Observation period duration: The duration of the observation period will be of 3 months +/- 2 
weeks, which corresponds to the time between the first appointment at the clinic during which the 
participants will take the vitamin D bolus and the second appointment. Because this study is a 
project which is realised in the context of a master’s degree, we chose this duration for the 
observation period so the data could be collected in the proposed sample of patients in the time that 
we have for that type of study. Although 3 months is a short duration to obtain meaningful clinical 
improvements, the primary objectives of this study are to evaluate the feasibility, the acceptability 
and the security of the proposed intervention.  
Supplement preparation: The supplier Euro-Pharm will provide the placebo and vitamin D3 
preparations (50,000 IU/mL) in coded bottles. Pharmacy will obtain the allocated treatment through 
a web-based randomisation system and will prepare the 6-mL bolus in coded syringes.   
Supplement administration: Upon randomisation, the research nurse will administer the syringe to 
the participants and provide the prescription for the daily dose. Participants will be requested to 
return pillboxes at the end of the study period, coinciding with their next follow-up visit to the clinic 
(i.e. 3 months +/- 2 week-window).    
Compliance assessment: Compliance of bolus retention will be visually assessed by the nurse while 
compliance to daily regimen will be assessed through pill counts. To maximize compliance, the 
research trainee will make weekly phone calls in order to gather information on compliance to daily 
regimen. In addition, pharmacies will be contacted to check if the prescription has been filled.   
Sample size: Based on our preliminary data, only 6% of SCD children had vitamin D sufficiency 
(≥75nmol/L). One of our objectives is to bring this proportion to 80%. To detect such an increase 
with a power of 0.90 and a α=0.05 by 2-tailed testing, we need 30 patients per group. Taking into 
account an attrition rate of 20%, we aim to recruit a total of 72 participants (36 per group).  
Outcomes:   
1. Feasibility and acceptability: Information pertaining to: i) identification and number needed to screen 
to identify eligible candidates; ii) willingness of patients and parents to participate in the study and of 
clinicians to recruit; iii) reasons and rates of refusal, recruitment and attrition, and burden of 

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participation; iv) response rates to questionnaires and compliance to the interventions will be 
gathered throughout the trial by the research trainee.   
2. Safety: Urine will be collected by the research nurse at baseline and 3 months and 
calcium/creatinine ratio measured using automated methods (Clinical Biochemistry Service, Sainte-
Justine). At baseline, participants will be provided with a container to collect urine on day 7 (± 3days) 
post-bolus along with the team endocrinologist’s prescription for the assessment of urine calcium 
and creatinine. They will be instructed to bring the urine to the nearest medical clinic for 
measurement. Results will be communicated to the team endocrinologist for evaluation and 
management. Serum calcium will be measured if deemed necessary by the endocrinologist. Code 
breaking will be done only if required for patient management. The proportion of children with 
episodes of hypercalciuria, hypercalcemia or serum 25OHD levels > 250nmol/L as well as any other 
adverse health effects will be documented at endpoint while weekly follow-up phone calls will be 
made by the research trainee to inquire about adverse events.   
3. Dietary intakes and sun exposure: The research trainee will assess calcium and vitamin D intakes at 
baseline and endpoint by means of a validated food frequency questionnaire15. Analysis of the FFQ 
will be based on values from the Canadian Nutrient File version 2010 and the US Department of 
Agriculture National Nutrient Database for Standard Reference as done previously16. Sun exposure 
will be evaluated with a non-validated questionnaire at both timepoints.   
4. Mean change of 25OHD levels: To measure this outcome, blood will be collected at baseline and 3 
months post bolus by the research nurse. Serum 25OHD will be measured in batches by tandem 
mass spectrometry at the Clinical Biochemistry Service of Sainte-Justine UHC.    
5. Clinical outcomes:  
Those outcomes will be either collected or measured at baseline and endpoint:  
(i) Growth: weight, height and BMI will be retrieved from medical records.  
(ii) Haematological: complete blood count, lactate deshydrogenase (as index of hemolysis), bilirubin 
and creatinine. These assessments are routinely performed in these children and will be extracted 
from medical records.  
(iii) Inflammatory: serum TNF and IL-6 will be measured by ELISA kits in Dr Mailhot’s lab.  
(iv) Bone health and musculoskeletal pain: serum PTH and biochemical markers of bone formation 
(P1NP) and resorption (C-telopeptides (CTX)) will be measured by standard methods in the Clinical 
Biochemistry Service, Sainte-Justine or using ELISA kits in Dr Mailhot’s lab. Musculoskeletal pain 
will be assessed with the Brief Pain Inventory (BPI) 17. This questionnaire provides information on 
the variability of pain intensity as well as on the quality of the pain felt by patients. It takes 
approximately 10 minutes to complete and will be administered by the research trainee to the 
participants or their parents (in case of young children).  
(v) SCD-related complications: Other complications affecting bone (e.g. fractures, avascular necrosis, 
osteomyelitis, bone infarct), the kidneys (e.g. nephrocalcinosis, microalbuminuria), the retina (e.g. 
retinopathy), blood vessels (e.g. stroke, thrombosis), the heart (cardiomegaly, tachycardia), the lungs 

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(e.g. asthma, pulmonary hypertension), the spleen (splenomegaly, spleen sequestration crisis), the 
liver and gallbladder (e.g. hepatomegaly, hepatic cytolysis, cholelithiasis, cholecystitis) will be noted. 
(vi) Quality of life: Health-related quality of life will be assessed through the Pediatric Quality of life 
inventory (PedQL). This 23-item validated questionnaire18 covers four domains: physical, emotional, 
social and school functioning, takes less than 4 minutes to complete and will be administered by the 
research trainee separately to the children and their parents.    
 
General characteristics of the participants, such as age, sex, genotype in regards of SCD, ethnicity 
and drugs taken by the participants will also be collected from medical records. 
 
Data collection will be entirely performed by the research trainee and supervised by the two principal 
investigators. 
 
Feasibility: Preliminary data showed that we already have access to a large cohort of patients 
(n=307) through our ongoing collaboration with two SCD expert haematologists. Infrastructure is 
already in place since we have previously performed data collection in more than a third of the SCD 
population (n=116) followed up at the clinic. Study is not invasive as those children have their blood 
drawn at each follow-up visits. Although a certain level of involvement is required from participants 
and their parents, we believe that a nutritional intervention will be perceived as more acceptable than 
a pharmacological treatment. For all these reasons, we anticipate few recruitment issues. 
Supplements (both boluses (placebo and vitamin D3) will be provided by Euro-pharm at no cost for 
the study. Ethics approval will be sought and a no-objection letter will be requested from Health 
Canada, pending results of this review. The no-objection letter is required given that the proposed 
total amount of vitamin D3 exceeds the upper intake level (UL) of vitamin D recommended for 
otherwise healthy children aged 4-8 years (i.e. 3,000 IU) and 9 and older (i.e. 4,000 IU).  

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Fig.1 Experimental design 
 
 
STATISTICAL ANALYSIS 
 
The analyses will be made using the intention-to-treat model where all subjects are included 
regardless of their adherence to the study protocol. Differences in outcomes between experimental 
groups at baseline and endpoint will be assessed using parametric Student’s t test or non-parametric 

November 30th, 2017; Version 1                                                                                                                              12 
 
Mann Whitney U test for continuous variables and Chi-square test or Fisher’s exact test for 
categorical variables. Intragroup differences will be assessed using paired Student’s t test with 
Bonferroni adjustment. Analyses will be performed under allocation concealment with unblinding 
occurring after trial completion and analysis of primary outcomes. Given the pilot nature of our 
study, subanalyses will be undertaken on variables that may potentially influence the response to 
vitamin D such as genotype, season of the year or baseline vitamin D status. However, these analyzes 
remain exploratory. 
 
CLINICAL SIGINIFICANCE 
 
By implementing this pragmatic and highly acceptable intervention and achieving a compliance of 
100% with the administration of the vitamin D bolus, we expect to: 1) correct vitamin D 
insufficiency in SCD children; 2) avoid monitoring their 25OHD levels on a regular basis; and 3) 
ultimately demonstrate improvements in clinical outcomes. 
 
The participation of 2 expert hematologists of the SCD clinic in this project is a great asset, because 
their implication will facilitate the knowledge translation brought by the research to the clinical 
practice. Furthermore, the eventual benefits of the study are of high clinical importance because they 
are easily implantable to the clinical practice and could lead to improvement in the nutritional status 
of these patients. Therefore, these patients could benefit from the intervention rapidly and could see 
their quality of life improved. Finally, our study is still at an early stage, because it is first and 
foremost an acceptability and feasibility study. The results of this study will give us the necessary data 
to inform a RCT at much bigger scale so it could benefit more children. The results of this study will 
also allow us to evaluate the incidence on the quality of life of the patients and on the onset of SCD 
related complications. 
 
ETHICAL ISSUES  
   
 
In this study, there will be an intervention, which is a vitamin D supplementation, regular and direct 
contacts with the participants by the administration of questionnaires at baseline and endpoint, and 
phone calls during the period of observation. The inform consent of the patients will be obtained 
before performing any intervention related to the study. Moreover, medical charts will be consulted 
at the beginning of the study to identify eligible patients for the study. The authorisation of the 
Medical and University Affairs Directorate will also be asked to consult the medical records. Finally, 
the project will be registered at Health Canada and a no-objection letter will be sought for the 
vitamin D3 bolus. The project will also be registered at clinicaltrials.gov. 
Risk of toxicity: The vitamin D supplementation that will be given to the children puts them at risk 
of toxicity given the high dose and the nature of the vitamin (fat-soluble vitamin, which can 
accumulate in the organism). However, we anticipate the risk of overdosing children with normal 

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baseline 25OHD levels to be minimal for the following reasons. First, a very small proportion of our 
cohort (i.e. 6%) had normal 25OHD levels (>75 nmol/L)2. Second, vitamin D toxicity is associated 
with high chronic intake and serum 25OHD levels > 250 nmol/L19. However, using a more 
conservative approach, the report on Dietary reference intakes (DRI) for calcium and vitamin D 
stated that 25OHD levels above 125 nmol/L may be associated with risks20. In our cohort, none 
displayed serum 25OHD considered toxic whereby the maximum 25OHD concentration achieved 
was 99 nmol/L, which is well below toxic levels2. Furthermore, the majority of blood draw were 
made in spring and in summer, 2 seasons in which we expect 25OHD serum levels to be higher due 
to sun exposure. Third, vitamin D bolus administration has not been associated with reports of 
toxicity in both non-SCD children (bolus of 300,000 and 600,000 IU) 21 and SCD patients (bolus of 
240,000 IU) 9. Thus, most of our participants are vitamin D deficient or insufficient and will likely 
benefit from raising their 25OHD levels.  Finally, given that the study includes only one vitamin D 
bolus and lasts only 3 months, the risk of toxicity for the patients is minimal.  
 
Use of a placebo: The use of a placebo in this study is justified by the fact that both groups 
(experimental and placebo) will received, in addition to the study intervention, a prescription for a 
supplementation of vitamin D3 of 1,000 IU per day, which corresponds to the current guidelines. 
Therefore, the children in the placebo group will not be exposed to higher risks of vitamin D 
deficiency. The difference of vitamin D received by experimental group (4, 625 IU) and the placebo 
group (1, 292 IU) should allow us to discriminate enough the effect of the intervention compared to 
the placebo. 
 
No pre-selection of children based on their baseline vitamin D status or season: All eligible 
SCD children will be asked to participate in this study regardless of their baseline vitamin D status or 
season of the year. The absence of pre-screening is justified by our preliminary data, which showed 
that a large proportion of SCD children are either vitamin D deficient or insufficient during 
summertime (insufficiency 33% and deficiency 66%) 2. Moreover, serum 25OHD levels of these 
children declined seasonally (45.6±19.5 nmol/L in summer vs. 33.9±15.9 nmol/L in fall, p=0.01). 
From these observations, we anticipate that nearly all SCD children would benefit from such an 
intervention. Although it is suggested that serum 25OHD > 75nmol/L is likely associated with extra-
skeletal benefits, the optimal target serum 25OHD is still unknown. Hence, by restricting the 
intervention to children with baseline vitamin D deficiency/insufficiency, we would exclude children 
that may benefit. The absence of pre-selection will also allow us to study the impact of the baseline 
status on the efficacy of the intervention in addition to facilitate the implementation of the 
intervention in clinic.   
 
 
 
 

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TEAM INFORMATION   
Principal investigator:   
Genevieve Mailhot, PhD, RD  
Associate professor, Department of Nutrition, Université de Montreal Researcher, CHU Sainte-
Justine Research Center   
Areas of expertise: vitamin D, calcium, bone health, inflammation, rare diseases, chronic diseases   
Roles: The PI is a PhD registered dietitian with specific training in vitamin D whereby she has 
accumulated more than two decades of experience. The PI will oversee study logistics along with her 
research trainee, supervise data collection, and lead the data analysis, manuscript writing, team 
meetings and knowledge dissemination. Her lab personnel will process the blood samples and 
perform measurements using ELISA kits.   
 
Nathalie Alos, MD   
Endocrinology Division  
Department of pediatrics  
CHU Sainte-Justine  
Researcher, CHU Sainte-Justine Research Centre   
 
Areas of expertise: vitamin D, bone health, metabolic bone diseases   
 
Roles: Dr Alos is a pediatric endocrinologist and the director of the Pediatric Bone Health Unit at 
the CHU Sainte-Justine. She will prescribe the daily vitamin D and calcium supplements and oversee 
all safety aspects of the intervention. She has collaborated to the design of the research protocol and 
will be involved in data analysis and interpretation, manuscript editing, and knowledge dissemination.         
  
Co-investigators:   
 
Sylvie LeMay, PhD, RN  
Professor  
Faculty of nursing  
Université de Montréal  
Researcher, CHU Sainte-Justine Research Centre   
 
Areas of expertise: musculoskeletal pain, pain measurement   
 
Roles: Dr Le May is a PhD registered nurse who will provide expertise regarding pain issues, 
measurement and analyses, as well as review drafts of the manuscript following completion of the 
study.   

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Yves Pastore, MD  
Hemato-oncology Division  
Department of pediatrics  
CHU Sainte-Justine   
Areas of expertise: hematology, sickle cell disease   
Roles: Dr Pastore is one of the haematologists who will be responsible for enrolling the patients. He 
has collaborated to the design of the research protocol and will be involved in data analysis and 
interpretation, manuscript editing, and knowledge dissemination.     
Nancy Robitaille, MD  
Hemato-oncology Division  
Department of pediatrics  
CHU Sainte-Justine   
 
Areas of expertise: hematology, sickle cell disease   
 
Roles: Dr Robitaille is the other haematologist involved in patient’s recruitment. She has also 
collaborated to the design of the research protocol and will be involved in data analysis and 
interpretation, manuscript editing, and knowledge dissemination as well.     
 
Research trainee   
 
Pascale Grégoire-Pelchat is a registered dietitian who performed the cross-sectional study (Vitamin 
D status in a Canadian cohort of children with SCD, manuscript submitted) as a research internship 
project. The proposed project will be the topic of her master studies scheduled to begin in 
September 2017. She will oversee all study logistics in collaboration with the PI. She will be 
responsible for ethics submission, screening participants for enrollment, assisting the haematologists 
for recruitment, meeting with the parents to administer the food frequency, sun exposure, the Brief 
Pain Inventory and PedQL questionnaires, retrieving laboratory results and data from medical 
records, performing data analysis and dissemination, and drafting the manuscript.   
  
Other collaborator   
Euro-Pharm: Euro-Pharm is a pharmaceutical company, which manufactures and distributes 
vitamin D oral preparations for children. They will supply the vitamin D and identical placebo oral 
supplement for the proposed number of patients and will provide all documentation required to 
fulfill Health Canada requirements. They will have no input on the design and the conduct of the 
study as well as on the analysis and interpretation of the data.   

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TIMELINE  
   
 
We plan to carry out this project over a 2-year period. Timeline will be divided into three major 
segments:   
i) Ethics application and approval, and study set-up: October 2017-April 2018 (5 months)  
ii) Patient recruitment, data collection, sample processing and analysis: May 2018-March 2019 (11 
months) 
iii) Data analysis, manuscript drafting and dissemination: March 2019-July 2019 (5 months) 
 
 
BUDGET 
 
This is a research project that is not subsidised. The vitamin D bolus and placebo will be provided at 
no cost by Euro-Pharm. The research trainee will be paid by two grants that she received ($9,500 
total + $1,000 from her director) and by her part time job (2 days per week) as a dietician which will 
fill the difference for the minimum intake required for master’s students. The other expanses will be 
covered by the research fund of the two principal investigators. 
 
KNOWLEDGE TRANSLATION  
   
 
Our key knowledge transfer goals are to increase knowledge and awareness to ultimately move 
research evidence into practice, improve patient’s nutritional management and the role of dietitian in 
that respect, and inform future research priorities. The CanHaem existing guidelines are based on 
minimal data, collected in individuals of different ethnic backgrounds.  Our study will thus provide 
additional evidence in a Canadian context that may prompt a change in clinical practice guidelines. 
To achieve the knowledge transfer goals, we will reach out to our target audiences via 1) 
presentations at international (e.g. American Society of Pediatric Hematology/Oncology (ASPHO)), 
national (e.g. Canadian Nutrition Society) and local conferences or to national/local groups and 2) 
peer and non-peer review publications in disciplines such as nutrition and hematology. Upon 
completion of the study, we will invite the study participants (parents and children) to a “Scientific 
Café” in order to present and discuss the results and gather their input and thoughts on the study 
and future participation.  Finally, the study results will also be presented at the annual Symposium for 
Sickle cell disease, which is an event intended for SCD patients and their family. 
 
 
 
 
 
 
 

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REFERENCES  
 
   
 
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sickle cell disease: a systematic review. PLoS One. 2015;10(3):e0119908. 
2. Grégoire-Pelchat P, Alos N, Ribault V, Pastore Y, Robitaille N, Mailhot G. Vitamin D intakes and 
status of children of predominantly Haitian and Sub-Saharan African origin with sickle cell disease. 
Submitted to Journal of Pediatric Hematology and Oncology. November 2017.  
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