Vitamin D status is associated with bone mineral density and bone mineral content in preschool-aged children.

This study examined the associations between vitamin D status, bone mineral content (BMC), areal bone mineral density (aBMD), and markers of calcium homeostasis in preschool-aged children. Children (n=488; age range: 1.8-6.0 y) were randomly recruited from Montreal. The distal forearm was scanned using a peripheral dual-energy X-ray absorptiometry scanner (Lunar PIXI; GE Healthcare, Fairfield, CT). A subset (n=81) had clinical dual-energy X-ray absorptiometry (cDXA) scans (Hologic 4500A Discovery Series) of lumbar spine (LS) 1-4, whole body, and ultradistal forearm. All were assessed for plasma 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone concentrations (Liaison; Diasorin), ionized calcium (ABL80 FLEX; Radiometer Medical A/S), and dietary vitamin D and calcium intakes by survey. Age (p<0.001) and weight-for-age Z-score (p<0.001) were positively associated with BMC and aBMD in all regression models, whereas male sex contributed positively to forearm BMC and aBMD. Having a 25(OH)D concentration of >75 nmol/L positively associated with forearm and whole body BMC and aBMD (p<0.036). Sun index related to (p<0.029) cDXA forearm and LS 1-4 BMC and whole-body aBMD. Nutrient intakes did not relate to BMC or aBMD. In conclusion, higher vitamin D status is linked to higher BMC and aBMD of forearm and whole body in preschool-aged children.

Vitamin D status in Montréal preschoolers is satisfactory despite low vitamin D intake.

The 2007 to 2009 Canadian Health Measures Survey reported vitamin D status in a representative sample of Canadians (6-79 y); however, children <6 y were not assessed. Our objective was to measure vitamin D intake from food and supplements, sun exposure, and biological vitamin D status of children ages 2 through 5 y in Montréal (latitude 45°N). Preschoolers (n = 508) were recruited between June 2010 and 2011 in a random sample of licensed daycares in the regions of greater Montréal, Canada in a cross-sectional study. The total plasma 25-hydroxyvitamin D [25(OH)D] concentration was measured using a chemiluminescence assay (Liaison, Diasorin). Dietary intake was assessed during one 24-h period plus a 30-d FFQ. Socioeconomic, demographic, anthropometry, and sun exposure data were collected. Plasma 25(OH)D was ≥50 nmol/L in 88% of children, whereas 49.4% had concentrations ≥75 nmol/L during the 1-y study. Almost 95% of preschoolers had vitamin D intakes less than the Estimated Average Requirement (EAR), and 4.8% of preschoolers ≤3.9 y and 25.9% of preschoolers ≥4 y had calcium intakes less than the EAR. Plasma 25(OH)D was different across age, income, sun index, milk intake, and dietary and supplemental vitamin D intake tertiles. Despite vitamin D intakes less than the EAR, the vitamin D status of Montréal preschoolers attending daycare is mostly satisfactory even in winter, suggesting that the EAR value is too high in the context of typical exogenous intakes of vitamin D in North America.

Forearm bone mineral density varies as a function of adiposity in inuit women 40-90 years of age during the vitamin D-synthesizing period.

Aging Inuit women are at increased risk for low vitamin D status due to habitation at higher latitudes, darker skin, and ongoing nutrition transition. Lower serum 25-hydroxyvitamin D (25[OH]D) concentration and higher risk of fracture have been separately reported in Inuit women, with particular relevance to postmenopausal women. We evaluated vitamin D status, forearm bone mineral density (fBMD), and nutrition in Inuit women ≥40 years. Women (n = 568) were randomly selected to participate in the 2007-2008 International Polar Year Inuit Health Survey from 36 Arctic communities. fBMD was measured using peripheral dual-energy X-ray absorptiometry. Dietary intakes were derived from 24 h recall and food-frequency questionnaires. Fasting serum 25(OH)D, parathyroid hormone, and osteocalcin (OC) were measured using a LIAISON(®) automated analyzer. The weighted prevalence of women having 25(OH)D concentration below 37.5, 50, and 75 nmol/L was 7.2 %, 17.6 %, and 48.6 %, respectively, with older women having better status. The dietary density of most nutrients increased with age, as did traditional food intake. fBMD was low in 3 (1.4 %) premenopausal (Z score < -2) and 107 (29.6 %) postmenopausal (T score < -1.5) women. Regression revealed that either weight, body mass index, or percent body fat significantly predicted fBMD in premenopausal women, in addition to age and OC in postmenopausal women. Women ≥50 years have higher vitamin D status and more nutrient-dense diets than women 40-49 years. While measures of adiposity predicted fBMD in all women, additional predictors after menopause included age and bone turnover.

Older age and lower adiposity predict better 25-hydroxy vitamin D concentration in Inuit adults: International Polar Year Inuit Health Survey, 2007-2008.

UNLABELLED: Our aim was to determine the prevalence and correlates of serum 25-hydroxy vitamin D (25(OH)D) concentration in Inuit adults. Low 25(OH)D concentration (< 50 nmol/L) was common; the strongest positive predictors were older age and healthy waist circumference. Nutritional health promotion and interventions along with longitudinal nutritional assessments are needed. PURPOSE: While 25(OH)D concentration of Canadian Inuit has not been examined on a large scale, Nutrition Canada Survey (1973) suggested that Inuit have low intakes of vitamin D. Our main purpose was to determine the prevalence and correlates of 25(OH)D concentration in a recent Inuit Health Survey. METHODS: Inuit adults (≥ 18 years) participated in the 2007-2008 International Polar Year Inuit Health Survey conducted in the months of August to October. Households were selected randomly in 36 communities. Dietary intake was assessed using a 24-h recall and a food frequency questionnaire. Anthropometric measurements, household living conditions, supplement use, and health status were assessed. In fasting samples, serum 25(OH)D and parathyroid hormone were measured using chemiluminesent assays (Diasorin, Liaison). RESULTS: Of the 2,595 participants, serum 25(OH)D was available on 2,207, of whom 67.4% and 42.2% had concentrations below 75 and 50 nmol/L, respectively. Further, 27.2% had values <37.5 nmol/L. Older adults (≥ 51 years) consumed higher quantities of traditional food and consequently had higher vitamin D intake than younger adults (18-30 and 31-50 years) (p < 0.05). The strongest positive predictors of 25(OH)D (≥ 50 or 75 nmol/L) among Inuit adults were older age and healthy waist circumference. CONCLUSIONS: This is the first population assessment of dietary vitamin D and 25(OH)D concentration in Inuit adults. The high prevalence of suboptimal 25(OH)D concentration noted in the late summer and early fall raises concerns of greater prevalence and more severe inadequacies in the winter.

Vitamin D status of Inuit preschoolers reflects season and vitamin D intake.

Rickets ascribed to hypovitaminosis D remains a public health concern among Aboriginal children in Canada and the United States. Our primary objective in this study was to investigate the prevalence and risk factors (gender, age, vitamin D intake, and socioeconomic status) for low vitamin D status of Inuit preschoolers living in 16 Arctic communities (51(o)N-70(o)N) and participating in the 2007-2008 Nunavut Child Inuit Health Survey. Children were selected randomly in summer (n = 282) and a follow-up was performed in winter for a subsample (n = 52). Dietary intake was assessed through the administration of a 24-h dietary recall and a FFQ. Anthropometric measurements (height, weight) were assessed. Plasma 25-hydroxy vitamin D was measured using a chemiluminescent assay (Liaison, Diasorin). Prevalence of vitamin D insufficiency (<75 nmol/L) among preschoolers was 78.6% and 96.8% in summer and winter, respectively. Median vitamin D concentrations and interquartile ranges in summer and winter were 48.3 (32.8-71.3) and 37.7 (21.4-52.0) nmol/L, respectively. The prevalence of vitamin D deficiency < 25 and < 37.5 nmol/L was 13.6 and 36.5%, respectively. Children who met or exceeded the adequate intake, those who consumed 2 or more milk servings (1 serving = 250 mL), and those who lived in households without crowding (47.7%) had a better vitamin D status than those who did not. The predictors of vitamin D status were dietary intake and age. Given low traditional food consumption and low consumption of milk, interventions promoting vitamin D supplementation may be required.