Effect of weekly vitamin D supplements on mortality, morbidity, and growth of low birthweight term infants in India up to age 6 months: randomised controlled trial

Objective To investigate whether vitamin D supplementation can decrease the mortality and morbidity of low birthweight infants in low income countries. Design Randomised controlled trial. Setting Large government hospital in New Delhi, India. Participants 2079 low birthweight infants born at term (>37 weeks' gestation). Main outcome measures Primary outcome was admission to hospital or death during the first six months of life. Main secondary outcome was growth. Interventions Weekly vitamin D supplements for six months at a dose of one recommended nutrient intake per day (35 mu g/week). Infants were visited weekly at home for observed supplementation and were brought to the clinic monthly for clinical examination and anthropometric measurements. Results Between group differences were not significant for death or hospital admissions (92 among 1039 infants in the vitamin D group v 99 among 1040 infants in the placebo group; adjusted rate ratio 0.93, 95% confidence interval 0.68 to 1.29; P=0.68), or referral to the outpatient clinic for moderate morbidity. Vitamin D supplementation resulted in better vitamin D status as assessed by plasma calcidiol levels at six months. In adjusted analyses, vitamin D treatment significantly increased standard deviation (z) scores at six months for weight, length, and arm circumference and decreased the proportion of children with stunted growth (length for age z score <= 2) or with arm circumference z scores of 2 or less. Conclusion A weekly dose of vitamin D resulted in better vitamin D status and benefited the classic vitamin D function of bone growth but did not decrease the incidence of severe morbidity or death among young low birthweight infants.