Bone mineral density of Inuit preschoolers in the Arctic Table V. Predictors of speed of sound of Inuit preschool children: Nunavut Inuit Child Health Survey, 2007 2008a,b Variables Age (years) BMI percentile categories (1B85th, 2 85th 95th, 3 ]95th) MUFA intake (g/d) Latitude degree (8N)c Constant Coefficient [95% CI] 1.26 [ 1.25 to 3.78] 8.34 [3.16 13.52] 0.23 [ 0.33 to 0.49] 0.59 [ 1.2 to 0.20] 1570.28 [1527.89 1612.67] p 0.32 B0.01 0.09 0.06 B0.01 aMultivariate linear regression. bThe number of hours spent outside, vitamin D status, latitude, sex, age, energy, protein, vitamin D and calcium intake did not contribute to the model. cLatitude ranged from 568 32? 728 40?N. between omega 3 and omega 6 and the ratio of omega 6: omega 3 due to the lack of the data in TF in the Canadian Nutrient File. Evidence suggests that BMD is positively correlated with omega 3 intake and is nega- tively associated with omega 6: omega 3 ratio in both men and women (38). Further, children in the higher 2 BUA or SoS quartiles did not have higher milk intake, dairy intake, TF intake, and monthly consumption of fish and marine mammals. All of these dietary variables were consumed scarcely, for instance mean daily milk intake of Inuit preschoolers was below 1 serving (data derived from the 24 h recall) and almost one-third of children did not consume fish and marine mammals in the previous month (data derived from the FFQ). Accordingly, it might be difficult to detect statistical differences in SoS or BUA. Several investigations have evaluated the role of calcium intake in bone health. Strong evidence suggests that calcium intake and absorption from childhood through early adulthood, is a crucial determinant of bone health throughout life (39), however, in the current study, this association was not detected, in contrast to the hypothesis. This observation is similar to another study among a large sample (n 1,016) of children (6 13 years old) in Taiwan (29). It has been suggested that cross-sectional studies are less sensitive in finding the influence of calcium intake on bone health, in compar- ison to prospective studies involving calcium interven- tions (40). Recently, we published nutrient intakes of Inuit preschoolers using all available 24-h recall data (n 374) (12). Mean intake of most nutrients, including protein, vitamin D and calcium was above the recom- mendations set by the Institute of Medicine (19). Only 8.8 and 24.0% met the recommended daily servings of fruits and vegetables and dairy products, respectively, of Canada’s Food Guide for First Nations, Inuit and Me´tis. The strength of this study is that, to our knowledge, it is the first to assess bone parameters in Inuit children, in combination with vitamin D intake, age, gender, latitude, BMI and other known predictors of bone health. However, the study findings cannot be generalizable beyond Inuit preschoolers and because the study was cross-sectional in nature, causality cannot be inferred. Further, for PTH measurements, intact PTH assays were used, instead of bioactive 1 84 PTH assays, that might have cross-reacted with carboxyl-terminal PTH fragments and lead to an overestimation of biologi- cally active PTH (41). Physical activity was not assessed among Inuit preschoolers, and the literature has shown positive association between physical activity and bone health (39), future studies should take this factor into consideration. It is very challenging to measure physical activity in such a young population. Measuring physical activity through a pedometer or accelerometer would be an accurate measure; however compliance issues are problematic among preschoolers. Even though, peripheral quantitative ultrasound is the most suitable method to assess BMD in large populations in the field for its several advantages, being easy, portable, safe, cost- effective, rapid, and radiation-free, this technique is limited by the difficulty to compare its results with those of the dual-energy X-ray absorptiometry (16). In summary, these data suggest that factors in support of bone health in young Inuit children are higher MUFA intake, older age and BMI. Since the dietary data was mainly derived from the 24 h recall data, further investigation assessing usual intakes of TF and nutrients affecting bone health using multiple 24 h recalls and FFQ along with serial assessment of vitamin D status of Inuit children across different seasons is required to confirm this observation. Further, future studies should assess physical activity, including weight bearing activities, and body composition, particularly body fat, as important predictors of bone health. Acknowledgements We thank Mrs Nelofar Athar Sheikh for her contribution in the data management and statistical advice, Mrs Louise Johnson-Down for her assistance in the analysis of the dietary data, Mrs Sherry Agellon for her help with the measurements of 25(OH)D and PTH concentrations, Mrs Angela Pacey for the data entry of BMD measures. Citation: Int J Circumpolar Health 2012, 71: 18999 - http://dx.doi.org/10.3402/ijch.v71i0.18999 7 (page number not for citation purpose)