Severe vitamin D-deficiency and the health of North China children

Objectives : To determine the health and nutritional status of rural Chinese children ages 12–24 months. Methods: This study used a cross-sectional design with a longitudinal component. Anthropometry and blood chemistry were measured on each child twice (n = 250). Caretaker knowledge and behaviors that relate to the child’s health and diet were evaluated by interview. Results: Children were taken outdoors at an average age of 131.8 days. 65.3% of surveyed children had serum 25-OH-D levels less than 12 ng/ml in the spring. This declined to 2.8% in the fall. Mean blood lead levels were 15.7 ± 11.0 μg/dl in the spring declining to 12.4 ± 12.5 μg/dl in the fall (t = 6.47, P = 0.000). This still left 63.5 and 54.9% of the children with toxic blood lead levels in spring and fall. Rates of respiratory disease declined significantly from spring to fall. A summer outdoors remarkably improved vitamin D-deficiency and lead toxicity. However, nutritional status worsened as during the summer diet was unable to keep up with growth and increased nutritional demand. From spring to fall serum zinc declined from 0.77 ± 0.19 to 0.66 ± 0.21 μg/ml (t = 3.33, P = 0.001) and blood hemoglobin declined from 12.5 ± 1.2 to 12.0 ± 1.2 gm/dl (t = 4.07, P = 0.000). Conclusions: Northern climate and cloistering of children creates a host of health risks for north China children. Vitamin D-deficiency, lead poisoning and respiratory disease are significantly worse during the winter months. These children need vitamin D supplementation during the winter and improved overall nutritional status during the summer to maintain ideal growth and development.