Efficacy of Prophylactic Supplementation

Preschool children Giving children living in areas where vitamin A deficiency is prevalent a large dose (i.e., 200 000IU or 60 mg Retinol Equivalent (RE)) of vitamin A every 4-6 months has been shown to reduce the risk of both noncorneal and corneal xer-opthalmia by 90%, increase serum retinol levels for 1-2 months following supplementation, and reduce young-child mortality by an average of 23% when coverage levels of at least 80% are achieved in deficient populations. In populations deficient in vitamin A, prophylactic supplementation of preschool children is one of the most cost-effective public-health interventions to improve the survival of children aged between 6 months and 6 years.

Post-partum women High-dose vitamin A supplementation is also recommended for post-partum mothers within 6 weeks of delivery, when the chance of pregnancy is remote, because the physiological demands of pregnancy and lactation deplete the mother's vitamin A stores. The provisional recommendation of the International Vitamin A Consultative Group is to give two doses of 200 000 IU at least 24 h apart to all women living in areas where vitamin A deficiency is prevalent and to give the supplement as soon as possible after delivery in order to maximize the beneficial effects on maternal vitamin A status, breast-milk vitamin A concentrations, and subsequent infant vitamin A status. Spacing the two doses by at least a day minimizes the risk of raising breast-milk retinoic acid (a short-lived metabolite of vitamin A) to potentially toxic levels.

Newborns and young infants Two randomized controlled trials in Asia that provided 50 000 IU of vitamin A to infants in the first 2 days of life found significant reductions in infant mortality among the vitamin A supplemented newborns. A third, confirmatory, trial is currently underway in Bangladesh, which, depending on the findings, may lead to newborn dosing recommendations. The current World Health Organization (WHO) recommendation is to provide 50 000 IU of vitamin A to infants with each of the three doses of diphtheria, pertussis, and tetanus at 6,10, and 14 weeks of age to improve vitamin A status. Further trials, however, are needed to confirm the benefit of implementing this recommendation for early infant vitamin A status, morbidity, and survival.

Pregnant women Where maternal night blindness or biochemical vitamin A deficiency is highly prevalent, prophylactic supplementation with up to 10000IU daily or 25 000 IU weekly has been given safely. The efficacy of low-dose maternal supplementation is still under investigation, but a recent community-based randomized placebo-controlled study in Nepal reported a 40% reduction in pregnancy-related maternal mortality among women given low doses of vitamin A or ^-carotene, provided as a weekly supplement, during pregnancy and for 3 months post-partum. This is the first trial to link vitamin A supplementation and maternal survival. Confirmatory efficacy trials are underway in Bangladesh and Ghana and should provide guidance on future maternal vitamin A supplementation recommendations.

The Mediterranean Diet Meltdown

The Mediterranean Diet Meltdown

Looking To Lose Weight But Not Starve Yourself? Revealed! The Secret To Long Life And Good Health Is In The Foods We Eat. Download today To Discover The Reason Why The Mediterranean Diet Will Help You Have Great Health, Enjoy Life And Live Longer.

Get My Free Ebook


Post a comment