Nutrition

Mechanistic studies on vitamin A in newborn health

Research on the biological mechanisms of the effects of vitamin A supplementation given in the first days of life.

Background

Vitamin A deficiency among the world’s poor and underprivileged populations is a considerable public health problem, as it can lead to blindness, decreased immune function and ultimately death. Its causes include poverty, infections and lack of access to traditional foods that historically have provided adequate provitamin A.

Vitamin A supplementation has been promoted as an essential child survival intervention in children 6–59 months of age. Interest in vitamin A supplementation in the neonatal period (0–28 days) has been sparked by several trials showing a reduction (15–64%) in infant mortality while other trials show no effect on infant mortality.

The Department of Nutrition for Health and Development (NHD) is currently supporting research to expand knowledge on the role of vitamin A in immunology and the metabolism of vitamin A in early life, to help establish the biological plausibility of vitamin A supplementation in reducing neonatal mortality.

Goal

Generate evidence to better understand the biological mechanisms through which vitamin A supplementation in the first days of life may have an impact on infant survival in order to inform global policy.

Objectives

  • Understand how a large dose of vitamin A given on the first day of life is absorbed, transported and distributed in body tissues.
  • Determine if a large dose of vitamin A given early in life improves newborn vitamin A stores. If so, to understand the magnitude and duration of impact.
  • Determine if a large dose of vitamin A given early in life affects organ maturation.
  • Determine if a large dose of vitamin A given on the first day of life affects innate and adaptive immune responses.

One animal study using the sow-piglet dyad model is being conducted by the University of Wisconsin to assess the efficacy of storage and distribution of graded oral doses of vitamin A in essential organs and detoxification mechanisms of vitamin A metabolism. Additionally, two human double-blind, placebo-controlled trials are being conducted to determine the effect of neonatal vitamin A supplementation on immune responses in early infancy.

These studies are examining the effect of 50 000 IU of vitamin A, given orally as a single dose within 48 hours of birth, followed by routine vaccinations, on immune function, including thymus maturation and function, systemic and mucosal immune responses to routine immunizations, regulation of immune responses and bacterial translocation. The human studies are being conducted in Dhaka, Bangladesh (n=300) and Sukuta, The Gambia (n=200).

Informing global policy

These studies have been made possible through a grant from the Bill & Melinda Gates Foundation.

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Contact information

Dr Lisa Rogers
Evidence and Programme Guidance (EPG) Unit
Department of Nutrition for Health and Development (NHD)
Geneva, Switzerland
Fax:+41 22 791 4156
Email: nutrition@who.int