Multivitamin supplementation of mothers during pregnancy and breastfeeding is associated with significantly higher weight at two years of age in children born to HIV-positive women, according to findings from a Tanzanian study published in the April edition of the American Journal of Clinical Nutrition. Low weight for age and growth failure are strongly associated with an increased risk of death in children born to HIV-positive mothers, whether or not the child is infected with HIV.
The study was designed to evaluate the effects of various combinations of multivitamins on mother to child HIV transmission and maternal and infant health, and its negative findings regarding the impact of supplementation on mother to child transmission have been published previously (Fawzi 2000).
The investigators have also previously reported that multivitamin supplementation results in greater birth weight and fewer births of infants that are smaller than expected for any given duration of pregnancy (small-for-gestational-age births).
The new report on the study analyses follow-up collected for up to two years after birth, and covers 886 single infants born to HIV-positive mothers.
Multivitamin supplementation took place during pregnancy and for at least two years after delivery, with mothers randomised to one of three multivitamin combinations or to a placebo. Children received a vitamin A supplement at six monthly intervals from month 6.
The study was designed to test a number of comparisons (in what is known as a multi-factorial design):
- between multivitamins alone or multivitamins plus daily vitamin A (5000 IU) and beta carotene (30mg)
- between the effects of giving a high dose of vitamin A (200,000 IU) at the time of delivery and no additional supplement at delivery
- between each of these approaches and a placebo.
The multivitamin supplement contained 20mg of thiamine, 20mg of riboflavin, 25mg of vitamin B-6, 100mg of niacin, 50ug of vitamin B-12, 500mg of vitamin C, 30mg of vitamin E and 0.8mg of folic acid. All women received 120mg of ferrous iron and 5mg of folate daily.
The median duration of follow-up was 21 months, but nearly one quarter of children died before the end of the study, and 29% of children had been diagnosed with HIV by the end of the follow-up period.
The effect of maternal multivitamin supplementation was sustained from birth weight throughout the 24 months follow-up period, with the effect most strongly evident in children who became HIV-positive. Across the entire study population, supplementation of multivitamins alone (without vitamin A and beta carotene) resulted in an average weight advantage of 459g (p=0.03). In children who were HIV-positive, supplementation of multivitamins alone resulted in a weight advantage of 1332g (p=0.01). This effect became stronger after 18 months of follow-up The effect of multivitamin supplementation was still evident, but less pronounced, in children of mothers who received vitamin A and beta-carotene in addition to a multivitamin supplement.
Multivitamin supplementation that included vitamin A and beta-carotene reduced the risk of wasting among children who were not wasted at birth by 47% (p=0.01).
The authors suggest that multivitamin supplementation affects post-natal growth by improving the levels of nutrients in breast milk, and they have previously reported that children of mothers in this study who received multivitamins had a lower rate of diarrhoea and higher CD4 cell counts, indicating stronger immunity (Fawzi 2003). Virtually all infants in this study were breast-fed; 94% were still breast-feeding at twelve months, 78% at 18 months and 22% at 24 months. Whether the effect of multivitamins on growth would be evident in infants not breast-fed after month 6 (as practiced in a number of recent trials in developing countries) is not clear from these data.
They conclude that the benefits for child growth reported in this study further strengthen the case for multivitamin supplementation in people with HIV, which has already been shown to delay disease progression.
Fawzi WW et al. Randomized trial of vitamin supplements in relation to vertical transmission of HIV-1 in Tanzania. J Acquir Immune Defic Syndr 23: 246-54, 2000.
Fawzi WW et al. Effect of providing vitamin supplements to human immunodefiency virus-infected lactatin mothers on the child’s morbidity and CD4+ cell counts. Clinical Infectious Diseases 36: 1053-62, 2003.
Villamor E et al. Vitamin supplementation of HIV-infected women improves postnatal child growth. Am J Clin Nutr 81: 880-8, 2005.