Vitamin A
Overview
Vitamin A Deficiency (VAD) is a widespread and critical public health issue, particularly affecting children and pregnant women in low- and middle-income countries (LMICs). It is a leading cause of preventable blindness in children and significantly increases the risk of severe infections and mortality.
Vitamin A (Retinol) is a fat-soluble vitamin essential for human health. It is found in many animal-based products, especially in the form of retinyl ester, and is crucial for vision, cellular differentiation, organ development, reproduction, and immune function. Fruits and vegetables are also excellent sources, primarily containing carotenoids, which are precursors to vitamin A.
Globally, an estimated 250 million preschool children are vitamin A deficient. This severe deficiency contributes to approximately 2% of deaths in children under five. Tragically, 250,000-500,000 vitamin A deficient children become blind each year, with half of them dying within 12 months of losing their sight due to the severity of their deficiency. In pregnant women, VAD can cause night blindness and may increase the risk of maternal mortality.
The burden of VAD is not uniform. In 2019, VAD and marginal VAD (mVAD) affected 333.95 million and 556.13 million children and adolescents in 165 LMICs, respectively. The prevalence of both VAD and mVAD was highest in children aged 0-5 years, at 19.53% and 28.22% respectively. Sub-Saharan Africa, especially central sub-Saharan Africa, and low socio-demographic index (SDI) regions continue to experience the highest age-standardized incidence and DALY rates of VAD.
Key Impacts of Vitamin A Deficiency
Ocular Health: VAD is the foremost cause of preventable blindness worldwide. It progresses from night blindness to xerophthalmia, which can involve corneal xerosis, ulceration, and keratomalacia, ultimately leading to permanent blindness.
Immune Function: Vitamin A is crucial for maintaining a healthy immune system. Deficiency weakens the body's ability to fight off infections, increasing susceptibility to severe illnesses like measles and diarrhoea, and raising the risk of associated mortality.
Growth and Development: VAD has adverse impacts on child growth and development. It is linked to stunting and anemia.
Maternal Health: In pregnant women, VAD can lead to night blindness and an increased risk of maternal mortality.
Diverse Sources of Vitamin A
Vitamin A (Retinol) is a fat-soluble vitamin essential for human health. It is found in many animal-based products, especially in the form of retinyl ester, and is crucial for vision, cellular differentiation, organ development, reproduction, and immune function. Fruits and vegetables are also excellent sources, primarily containing carotenoids, which are precursors to vitamin A.
Preventable Crisis: Interventions and Funding
The good news is that VAD is largely preventable. Various interventions have been implemented to address this deficiency:
Vitamin A Supplementation (VAS): This is one of the most common and cost-effective interventions. Providing high-dose vitamin A capsules to children aged 6–59 months every four to six months can dramatically reduce mortality from common illnesses and prevent blindness. It costs approximately $0.04 per child per year or around $1.23 per supplement to deliver, making it exceptionally cost-effective (estimated at $10-$20 per DALY averted). VAS programs initiated in the 1990s have shown a significant reduction in childhood mortality and morbidity.
Food Fortification: Many countries fortify staple foods with vitamin A.
Dietary Diversification: Encouraging communities to grow and consume a variety of vitamin A-rich foods, such as dark leafy green vegetables, milk, liver, and fish, is a sustainable long-term strategy.
Biofortification: Genetically modified crops, like Golden Rice, which provides more dietary vitamin A, are being developed and trialed to offer additional dietary sources in regions where rice is a staple.
Despite the proven effectiveness of interventions and the relatively low cost of prevention, VAD remains a significant challenge. Less than two-thirds of children aged 6-59 months in Eastern and Southern Africa currently receive adequate Vitamin A Supplementation. While significant investments are made in other global health issues, consistent and sustained funding for VAD programs is crucial to achieve its virtual elimination.
Leading Organisations and Initiatives
Leading organizations and initiatives involved in the fight against Vitamin A deficiency:
World Health Organization (WHO): Defines VAD as a major public health concern, provides guidelines for treatment and prevention, and supports Member States in VAD control programs.
UNICEF: Works to strengthen national systems and supports routine Vitamin A Supplementation (VAS) delivery, playing a key role in advocating for continued donor investment.
Helen Keller International (HKI): A long-standing leader in combating VAD, HKI implements successful VAS programs globally in partnership with national governments and local organizations, often acting as the lead NGO partner.
Nutrition International (NI): A Canadian-based, non-profit organization dedicated to ending malnutrition.
Global Alliance for Vitamin A (GAVA): A partnership including UNICEF, Centers for Disease Control and Prevention (CDC), Helen Keller International (HKI), and Nutrition International (NI), working to mobilize attention and resources for VAS programs.
Further reading
Vitamin A Deficiency in the MENA region: This study examined the burden of VAD from 1990 to 2019 in the Middle East and North Africa (MENA) region.
Golden Rice: Assessment of the RUTF market.
Vitamin A in a New Age (UNICEF): 2024 progress report
The prevalance of vitamin A deficiency(J Glob Health): A systematic review on modelling analysis.
Opportunities to give
The following malaria charities are currently recommended as particularly impactful by the independent charity evaluator GiveWell.
Helen Keller International’s Vitamin A Supplementation Program: Helen Keller provides funding to governments to deliver VAS campaigns for preschool age children. It also provides technical support on various aspects of these campaigns including planning, training of distributors, and promoting awareness of the campaign, and conducts monitoring to understand how many children are reached.
