Vitamin A deficiency is the leading cause of preventable blindness in children, and also substantially increases the risk of a child dying from diseases such as diarrhoea and measles.
An estimated 250 million preschool children are vitamin A deficient and a high proportion of pregnant women in low and middle income countries also suffer from the condition.
The School’s researchers have been at the forefront of research into the condition since the 1980s, leading a series of randomised controlled trials in collaboration with the Ghana Health Service to evaluate the impact on maternal and child survival of various vitamin A supplementation strategies.
David Ross, Betty Kirkwood and Peter Smith, all now professors at the School, led the Ghana Vitamin A Supplementation Trials (VAST) Survival and Health studies in the early 1990s, which involved more than 23,000 children. These showed that four-monthly supplementation of children aged six to 59 months could save many children’s lives and could reduce the occurrence of severe episodes of illness, clinic attendances and hospitalisations. This became World Health Organization (WHO) policy in the 1990s.
The next question of whether supplementation linked to early infant vaccination could also save lives was tested in three large-scale trials in Ghana, led by Betty Kirkwood, India and Peru in the EPI-Plus study involving nearly 10,000 mother-infant pairs. This confirmed the safety of vitamin A supplementation in young infants, but showed no impact on their survival.
Betty Kirkwood also led the ObaapaVitA trial investigating the benefits of weekly vitamin A supplementation of women during the reproductive years, including during pregnancy and the postpartum period. This involved more than 200,000 Ghanaian women and showed that supplementation had no impact on their survival or their babies’ survival.
These trials have been instrumental in the development of revised WHO guidelines on vitamin A supplementation, published in 2011. The VAST trials made up nearly a third of the evidence of the impact of vitamin A supplementation on all-cause mortality in children aged six to 59 months and greatly influenced the recommendation which still stands that supplementation in that age range is a key child survival intervention. The EPI-Plus and ObaapaVitA trials led to reversals in global policies on supplementing women after birth and on infants during the first 6 months of life.
The School’s research also had a major impact in Ghana, leading to the establishment of the National Vitamin A Programme which had reached 93% of children aged six to 59 months with two doses of vitamin A per year by 2012. The recent reversal on policies of supplementing babies alongside early vaccinations and women after birth have led to substantial cost savings.
An important by-product of the trials has been the establishment of the Navrongo and Kintampo Health Research Centres in Ghana, which are making substantial contributions to global health research. For example, recently the Kintampo Centre was one of the seven African sites testing the RTS,S malaria vaccine.