Michael F. Holick
Children who take 2,000 IU per day of vitamin D are more likely to be vitamin D sufficient compared with participants taking lower doses closer to the recommended daily allowance of 600 IU per day, according to findings published in The Journal of Clinical Endocrinology & Metabolism.
Jennifer Sacheck, PhD, of the Friedman School of Nutrition Science and Policy at Tufts University in Boston, evaluated data from the Daily D Health Study on 604 children (mean age, 11.7 years; 46.5% overweight/obese; 59.6% racial/ethnic minorities) randomly assigned to vitamin D supplementation at 600 IU per day, 1,000 IU per day or 2,000 IU per day for 6 months. Serum 25-hydroxyvitamin D was measured in participants at baseline (October-December) and at 3 months (January-March), 6 months (April-June) and 12 months (6 months after supplementation). Researchers aimed to determine the effect of supplementation on achieving serum 25-(OH)D sufficiency in children at risk for deficiency.
Mean serum 25-(OH)D was 22 ng/mL; and 5.5% of participants were severely deficient (< 12 ng/mL) and 88.6% were insufficient (< 30 ng/mL) at baseline.
At 3 months, mean serum 25-(OH)D increased in all three groups with the greatest increase in the 2,000 IU per day group compared with the other two groups (P < .001). At 6 months, increases in serum 25-(OH)D remained, and the 2,000 IU group had higher mean serum 25-(OH)D (33.1 ng/mL) than the 600 IU (26.3 ng/mL) and 1,000 IU groups (27.5 ng/mL; P < .001).
Fewer participants in the 1,000 IU group were deficient compared with those in the 600 IU group (15% vs. 22.9%), and more became sufficient at 6 months (35.8% vs. 26.6%). Sufficient levels were achieved by 59.9% of the 2,000 IU group at 3 months, and fewer participants of that group remained deficient at 6 months (4.7%) compared with the 600 IU group (22.9%) and 1,000 IU group (15%). At 6 months, nearly all severe deficiency was eliminated in all dose groups.
At 12 months, all dose groups experienced a decrease in serum 25-(OH)D levels.
“The study clearly demonstrates that otherwise healthy children are at high risk or vitamin D deficiency and insufficiency and that 2,000 IUs daily is required to raise the mean blood level about 30 ng/mL as recommended by the Endocrine Society’s Practice Guidelines for maximum skeletal health,” study researcher Michael F. Holick, PhD, MD, professor of medicine, physiology and biophysics and director of the general clinical research unit and the Bone Health Care Clinic at Boston University Medical Center, told Endocrine Today. – by Amber Cox
Disclosures: The authors report no relevant financial disclosures.