Efficacy of daily 4,000 International Units (IU) versus 6,000 IU of oral vitamin D in vitamin D deficient children with overweight and obesity: An open-label randomized controlled trial.

BACKGROUND AND OBJECTIVES

Children with overweight/obesity are at increased risk of vitamin D deficiency. This study compares the efficacy and safety of 4000 International Units (IU)/day vs. 6000 IU/day oral vitamin D over 12 weeks for treating vitamin D deficiency and evaluates its impact on metabolic parameters.

METHODS

In this open-label randomized controlled trial, 90 children (5-18 years) with overweight/obesity and vitamin D deficiency (25 [OH]D < 50 nmol/L) were randomized to receive 4000 IU/day (Group A, n = 45) or 6000 IU/day (Group B, n = 45) along with calcium. Efficacy (25 [OH]D ≥ 50 nmol/L), safety (hypercalcemia, hypercalciuria, hypervitaminosis D), and metabolic impact (HbA1c, lipids) were assessed over 12 weeks. Trial registered with CTRI/2021/02/031591.

RESULTS

Sixty-eight children completed the study. Both groups showed significant increases in serum calcium and reductions in alkaline phosphatase and parathormone, with no inter-group differences. Group B showed a faster rise in 25(OH)D levels, with higher means at 4 weeks [66.3 (3.12) vs. 55.6 (2.92)] and 12 weeks [100.6 (3.42) vs. 79.3 (3.17) nmol/L]. At 12 weeks, sufficiency was achieved in 91.4 % (Group A) and 93.4 % (Group B). Mild, asymptomatic hypercalcemia was noted in 7 children (Group A-3, Group B-4; p = 0.70) and resolved spontaneously. No significant metabolic changes were observed in either group.

CONCLUSIONS

Both 4000 IU/day and 6000 IU/day of vitamin D were effective and safe for treating vitamin D deficiency in overweight or obese children, with no observed effect on metabolic parameters in either group. Higher doses may accelerate sufficiency; however, standard dosing remains effective, emphasizing the need for individualized treatment and monitoring.

IMPACT STATEMENT

Comparing 4000 IU/day to 6000 IU/day of vitamin D in children with overweight or obesity showed that both regimens were safe and effective in achieving sufficiency without either regimen influencing metabolic parameters. The higher doses allowed for a quicker attainment of optimal levels. While both doses effectively establish vitamin D sufficiency in the short term, long-term data are necessary to confirm their ongoing efficacy and safety over extended periods.

CLINICAL TRIAL REGISTRATION NO

CTRI (Clinical Trial Registry India) (CTRI/2021/02/031591). The protocol can be accessed at https://ctri.nic.in/Clinicaltrials/pmaindet2.php?EncHid=NTI2NTM=&Enc=&userName=.