Higher vitamin D intake is needed to achieve serum 25(OH)D levels greater than 50 nmol/l in Québec youth at high risk of obesity

Abstract

Background/Objectives: Vitamin D levels are often observed to be low in Canadian youth, despite the mandatory fortification of fluid milk. We identified modifiable correlates of plasma vitamin D concentrations to inform public health efforts to remediate low-vitamin D status. Subjects/Methods: We recruited 159 children aged 8-11 years, who were at at high risk of obesity, non-systematically during different seasons. Vitamin D status was assessed by measuring plasma 25-hydroxyvitamin D (25(OH)D) using a radioimmunoassay. Dietary intake, including vitamin supplements, was measured using three dietitian-administered 24 h diet recalls. Fat mass was measured by dual energy X-ray absorptiometry. Accelerometers were worn for 7 days to estimate physical activity. Independent correlates of plasma 25(OH)D concentrations were identified using multiple regression in an analysis controlling for season of measurement.Results: Approximately, 7% of youth had hypovitaminosis D (25(OH)D p37.5 nmol/l) during winter and spring when vitamin D levels are at their nadir. Only 55% of participants had vitamin D levels, which the Institute of Medicine considers optimal (25(OH)D 450 nmol/l). The mean dietary vitamin D intake, 6.6 mcg, was well below current recommendations set at 15 mcg. A serving increase in milk consumption and a s.d. increase in physical activity were associated with only a 2.9 and 2.1 nmol/l increase in plasma 25(OH)D, respectively. There was no association between 25(OH)D and adiposity. Conclusions: Our results indicate the challenges of obtaining adequate vitamin D intake from the current food supply to support a level of 25(OD)D 450 nmol/l.

Vitamin D and K status influences bone mineral density and bone accrual in children and adolescents with celiac disease

“…This is likely due to the fact that intake of these nutrients did not significantly increase on the GFD and remained persistently low, a finding that is supported within the literature, particularly in Canada where intakes of vitamin D are generally low in healthy children and adolescents (El Hayek et al, 2010;Ohlund et al, 2010;Wild et al, 2010;Mark et al, 2011). Although a few children were taking a vitamin supplement (n ¼ 5), these were consumed on an ad hoc basis, and likely did not contribute sufficiently to overall vitamin D/calcium nutriture and bone health.…”

Assessing Nutritional Quality and Adherence to the Gluten-free Diet in Children and Adolescents with Celiac Disease

“…Intakes of many nutrients were substantially lower than recommended intake levels in both groups. Most participants failed to meet the RDA of vitamin D. This is very similar to the general population of Canadian children [27,28] that indicates that suboptimal vitamin D intake in children with CD is not due to the GFD alone, but rather due to reduced intakes of vitamin D fortified dairy products in Canadian children [27][28][29][30]. Most children were only able to meet the RDA for vitamin D with daily vitamin D supplementation in the range of 600-1000 IU/D (predominantly in the form of a single vitamin preparation).…”

Definition of Vitamin D Deficiency in Schoolchildren: Systematic Review With Meta-Analysis

“…One study performed seasonal supplementation of 13,700 IU over seven days (TABLE 1). None of the studies reported side effects during supplementation (19)(20)(21)(22)(23)(24) . (24) 159 Canadian children of both sexes.…”

“…The reviewed articles differ in some respects such as the serum 25(OH)D values considered to be deficient, insufficient or adequate. Three of the six articles considered deficiency as levels below 20 ng/ mL (19)(20)(21) , one considered it as below 18 ng/mL (22) , another below 15 ng/mL (23) , and the latter below 11 ng/mL (24) . Therefore, half of the studies analyzed considered deficiency as below 20 ng/mL.…”

“…In addition, the low intake of food sources of calcium and vitamin D has been reported in several countries across all age groups (21,33) . Mark et al (2011) applied the 24-hour recall for three days in Canadian children, and vitamin D intake was below the current Canadian recommendation (23) .…”