VITAMIN-D PROPHYLAXIS IN CHILDREN WITH A SINGLE-DOSE OF 150000-IU OF VITAMIN-D

Objective: To determine the efficacy of a single oral dose of 150000 I U of vitamin D-2 at the beginning of autumn for preventing winter vita min D deficiency in children in Ushuaia (55 degrees S). Design: The st udy was prospective. Subjects: 79 children clinically healthy with 8.6 +/- 1.4 y of age (X +/- s.d.). Interventions: Fasting serum venous sa mples and 2 h urine samples were obtained immediately before and 6 w a nd 5 mon after the vitamin D dose. Parents informed consent was obtain ed previous to the study. In a subgroup of 30 children serum levels of calcium (sCa), phosphorus (sP), total alkaline phosphatase (TAP), 25 hydroxyvitamin D (25 OHD), parathyroid hormone (PTH) and the urine cal cium/creatinine ratio in a 2 h urine sample (UCa/UCreat) were measured . In the whole group sCa and the ratio uCa/ucreat were measured. Resul ts: After 150000 IU of vitamin D-2 administration, serum 25 OHD levels at the end of winter (17.0 +/- 9.4 ng/ml) were similar to those at th e beginning of autumn (18.7 +/- 10.7 ng/ml), but significantly higher from those obtained in a previous study without vitamin D (9.8 +/- 3.8 ng/ml, P < 0.001). PTH levels were higher at the end of winter (P < 0 .02), but this augmentation was lower than the increment observed with out vitamin D. Plasma calcium levels and the urine calcium/creatinine ratio were lower at 5 months after vitamin D-2 dose (P < 0.02 and P < 0.05 respectively). In the total group the serum calcium was lower aft er the fifth month (P < 0.05). The Uca/Ucreat ratio was lower at 6 w a nd 5 mon (P < 0.05 and P < 0.001). Conclusion: A single dose of 150000 IU of vitamin D maintained appropriate levels of 25 OHD without induc ing hypercalcemia nor hypercalciuria, but a winter increment of PTH (s maller than in the group without vitamin D) was not inhibited. Sponsor ship: Nestle Nutrition Research Grant Programme.