The Cochrane researchers reviewed data from 43 randomized trials, representing more than 200,000 children aged six to five years. They concluded that vitamin A supplementation is effective in reducing all-cause mortality by 24 percent, mainly via a reduced occurrence of measles and diarrhea.
“More than 190 million children are vitamin A deficient around the globe; reducing their risk of mortality by 24 percent could save almost 1 million lives per year,” said the researchers, led by Professor Zulfiqar Bhutta, Chairman of the Division of Women and Child Health at Aga Khan University, Pakistan.
However, the review said that supplementation is not a permanent solution to the problem of vitamin A deficiency, adding that more needs to be done to increase dietary intake of vitamin A in low and middle income countries.
Bhutta and colleagues said vitamin A deficiency is a major public health problem in low and middle income countries.
Deficiency in vitamin A pre-disposes children to an increased risk of a range of health problems – including respiratory diseases, diarrhea, measles and vision problems, and can eventually lead to death.
Because of this, the World Health Organization (WHO) recommends vitamin A supplements for pregnant mothers and children. However, there have been recent disputes regarding the effectiveness of supplementation programs in developing countries.
The review found overall effects for measles mortality were not statistically significant, but said the trend was consistent and supported the therapeutic effects of vitamin A in reducing measles.
Supplementation was also seen to reduce the incidence of diarrhea, with the authors noting that previous research suggests therapeutic use of vitamin A may prevent acute diarrhea from becoming chronic.
In addition to reducing death and illness, the review said that vitamin A supplementation reduces night blindness and potential precursors to blindness, such as Bitot’s spots and xerophthalmia.
“In our opinion, given the evidence that vitamin A supplementation causes considerable reduction in child mortality, further placebo-controlled trials of vitamin A supplementation in children between six months and five years of age are not required,” concluded Bhutta and colleagues.
They did however note the need for further studies comparing different doses and delivery mechanisms of vitamin A. They added that whilst supplementation may be an immediate solution to deficiency, adequate nutrition and long term solutions to underlying problems are needed.
“Fortification, dietary diversification, food distribution programs and horticultural developments such as home gardening and bio-fortification may provide more permanent relief,” said Bhutta. “For example, vitamin A content could be increased in staples such as rice or growers may aim to promote use of biofortified foods such as orange sweet potato.”
Source: Cochrane Database of Systematic Reviews
Issue 12, doi: 10.1002/14651858.CD008524.pub2
“Vitamin A supplementation for preventing morbidity and mortality in children from 6 months to 5 years of age”
Authors: A. Imdad, K. Herzer, E. Mayo- Wilson, M.Y. Yakoob, Z.A. Bhutta