Maternal and Infant Vitamin Status During the First Nine Months of Infant Life

Study Overview
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Brief Summary
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In this study the investigators wanted to assess vitamin D status and possible consequences of low plasma 25-hydroxyvitamin D levels in a population of healthy mothers and their infants, in the community of Aarhus, Denmark.

Detailed Description
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Danish people living at northern latitudes (56°N), often with overcast and foggy weather and few sunshine hours are at increased risk of vitamin D insufficiency. Although vitamin D is obtainable from fortified food and oily fish, the major source is the dermal synthesis of the vitamin D through exposure to solar ultraviolet light. In the 19th century rickets was endemic in northern Europe, and many children developed rickets, a severe bone-deforming disease. Encouragement of sensible sun exposure, supplementation with cod liver oil and fortification of milk with vitamin D, resulted in an almost complete eradication of rickets by the end of the 19th century. At present vitamin D deficiency seems again to be more widespread. The classical outcomes of severe vitamin D deficiency are rickets in growing individuals and osteomalacia in adults. Low vitamin D status also relates to low bone density and increased risk of osteoporotic fractures. Although the incidence of rickets has declined over the last decades, cases attributable to inadequate vitamin D intake and low exposure to sunlight continue to be reported, and maternal vitamin D status may have permanent effects on newborns' health. Pregnant women, newborns, breastfed children, and lactating women are at a high risk of vitamin D deficiency, especially during winter and early spring. Since fetal plasma 25-hydroxyvitamin D (25OHD) depends on maternal 25OHD, fetal vitamin D status may show seasonal changes parallel to those observed in the mothers. To prevent rickets and vitamin D deficiency in infants, most Western countries, including Denmark, recommend a daily maternal intake during pregnancy and lactation of 10 μg and that breastfed children are given a supplement of 10 μg of vitamin D/day. Despite these recommendations, approximately one third of Danish pregnant and lactating women have vitamin D insufficiency. However, childhood rickets is nowadays rare in Denmark, although it still exists especially among immigrants and mothers with prolonged lactation. Accordingly, in 2010, the Danish National Board of Health extended the recommendations for vitamin D supplementation to the first two years of life.

Official Title
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Vitamin D Status in the First 9 Months of Life

Conditions
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Rickets, Osteomalacia, Osteoporosis

Intervention / Treatment
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* Other: Blood and breastmilk samples


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy pregnant Caucasian women aged 24-41 years, A normal pregnancy giving birth between 38-42 gestational weeks. Exclusion Criteria: Chronic diseases, Other ethnic origin than Caucasian, and Alcohol or drug abuse.

Ages Eligible for Study
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Minimum Age: 24 Years
Maximum Age: 41 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Blood and breastmilk samples|The investigators collected maternal and infants blood samples from birth, and 4 and 9 months forward, including breastmilk from the mothers at all visits|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prevalence in plasma 25OHD and parathyroid hormone at birth | For determination of plasma 25OHD and plasma parathyroid hormone concentrations, the investigators sampled cord blood at baseline. Furthermore the investigators collected maternal blood at 2 weeks after birth (baseline). | at birth (baseline) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prevalence in plasma 25OHD and parathyroid hormone at 4 months | For determination of plasma 25OHD and plasma parathyroid hormone concentrations, the investigators sampled maternal and infants blood samples at 4 months (1. follow-up). | at 4 months | 
| Prevalence in plasma 25OHD and parathyroid hormone at 9 months | For determination of plasma 25OHD and plasma parathyroid hormone concentrations, the investigators sampled maternal and infants blood samples at 9 months (2. follow-up). | at 9 months |