Severe vitamin D deficiency in children from Punta Arenas, Chile: Influence of nutritional status on the response to supplementation

There is a high risk of vitamin D (VD) deficiency in the population of southern Chile that can be treated with VD supplements. Weight excess (WE) can influence the response to supplements. Objectives: To study the prevalence of VD deficiency and the effect of cholecalciferol (VD3) supplements in healthy children from Punta Arenas, Chile, and evaluate a possible association with nutritional status. Methodology: Demographic and anthropometric data, as well as laboratory assessment of serum 25-hidroxyvitamin D (25OHD) and other bone metabolism parameters were evaluated. After baseline evaluation, children were supplemented with VD3 1600 IU/day for one month, after which 25OHD was retested. Results: Of the 108 children studied, 50% were boys, and had a mean age of 9.6 +/- 0.5 years. Nutritional assessment showed that 39% had normal weight, 46% were overweight, and 15% were obese. Median 25OHD was 10.9 ng/ml: 96.3% had deficiency (< 20 ng/ml) and 3.7% insufficiency (20-29 ng/ml). Severe deficiency was found in 62% (< 12 ng/ml). Baseline 25OHD was not affected by nutritional status. After supplementation, median 25OHD was 17.5 ng/ml: 62% had deficiency, 36% insufficiency, and 2% sufficiency (> 30 ng/ml). Children with WE had a significantly lower increase in 25OHD than children with normal weight (5 +/- 5.5 vs. 7.7 +/- 4.9, p = 03). Children with WE may require 32% higher VD dose than normal weight children to attain the same 25OHD concentration. Conclusions: Chilean schoolchildren from Punta Arenas have high prevalence of WE and VD deficiency, with a majority in the range of severe VD deficiency. WE interferes in the response to VD supplementation, leading to a lower increase in 25OHD. (C) 2015 Sociedad Chilena de Pediatria. Published by Elsevier Espana, S.L.U.