[Administration of a single Winter oral dose of 200,000 IU of vitamin D3 in adolescents in Normandy: evaluation of the safety and vitamin D status obtained].

Adolescence, a period of growth and acquisition of bone mass, requires adequate calcium and vitamin D intake. This study was designed to assess the impact of a single loading dose of 200,000 IU of vitamin D(3) on the winter vitamin D status of healthy adolescents. Vitamin D status was assessed by 25-OH-D levels before, 3 weeks, and 3 months after this single dose, and safety was assessed by serum calcium and PTH and urinary calcium excretion in random samples from 27, 23, and 17 healthy adolescents derived from the same institution. The 25-OH-D peak value 2 weeks after the vitamin D supplement of 71-129 nmol/l (mean, 96 nmol/l), and a residual level at 3 months of 29-83 nmol/l (mean, 57 nmol/l) serum calcium and urinary calcium excretion expressed by the calcium/creatinine ratio were normal and stable at 2 weeks and 3 months, remaining less than 0.5 for the calcium/creatinine ratio. This simple measure, ensuring good compliance during adolescence, ensures optimal winter vitamin D status with no signs of overload.