Vitamin D Sufficiency through Sunshine in Infants?

Vitamin D is vital for human health, and its deficiency may result in hypocalcemic seizures and rickets in infants and children. The optimal cut-off of serum 25(OH)D levels to define vitamin D deficiency are yet to be established. While, the Endocrine Society of USA has suggested serum 25(OH)D < 20 ng/mL to define vitamin D deficiency [1], the Institute of Medicine (IOM), USA recommends a cut-off of 12.5 ng/mL of serum 25(OH)D [2] to define vitamin D deficiency. Despite abundant sunshine, biochemical vitamin D insufficiency and deficiency are reported to be quite prevalent in apparently healthy infants, children, adolescents and pregnant women in urban India [3-5]. Serum 25(OH)D levels <12.5 ng/mL were reported in 12-47% of under-five children and 4-28% in older children and adolescents [5]. The biological benefits and safety of routine long-term Vitamin D supplementation in breastfed Indian neonates are yet to be unequivocally demonstrated. In a randomized controlled trial from Delhi [6], directly supervised weekly vitamin D supplementation (1400 IU) in term low birth weight newborns for six months expectedly resulted in higher 25(OH)D levels, but there was no decrease in incidence of severe morbidity or death. There were borderline (~0.1 SD) increases in length, weight and arm circumference, but a paradoxical decrease in head circumference. At age 3-6 years, the supplemented infants were surprisingly borderline (~0.1 SD) thinner but importantly there were no differences in any of the evaluated functional outcomes [7].