Many people in the developing world do not get enough vitamin A or beta carotene from the food they eat, contributing to the serious public health problem of vitamin A deficiency.
Vitamin A is an essential nutrient needed for the visual system, growth, development, and a healthy immune system. Everybody needs vitamin A to grow and thrive, particularly mothers and young children.
Vitamin A is found in animal products and breastmilk. Carotenoids are substances like beta carotene that the body converts into vitamin A. They are found in orange-colored fruits and vegetables and in dark-green leafy vegetables.
Vitamin A deficiency
Vitamin A deficiency results from a lack of vitamin A in the diet. Vitamin A deficiency can also be caused by infections that reduce appetite or the body’s ability to absorb vitamin A.
Vitamin A deficiency can damage the immune system and decrease the body’s ability to resist or fight infections, therefore increasing the risk of mortality from common diseases, especially among young children. Vitamin A deficiency may also result in impaired vision, including night blindness (the inability to see at night or in dim light) and may result in permanent, partial, or total blindness if left untreated.
Providing adequate amounts of vitamin A, on the other hand, reduces overall child mortality by 23%.
Vitamin A deficiency is most common among young children and pregnant and nursing women as they have increased nutrient requirements.
The World Health Organization (WHO) estimates that 190 million preschool children and 19 million pregnant women are vitamin A-deficient globally. Children with vitamin A deficiency are more likely to suffer from poor health and premature death. Vitamin A deficiency is the leading cause of preventable blindness among children in developing countries. Each year, up to 500,000 children go blind as a result of this condition. Half of them die within 12 months of going blind.
The poor in the developing world, who live primarily on a diet of starchy staples that lack vital micronutrients like vitamin A (such as rice), are particularly vulnerable to vitamin A deficiency.
Vitamin A deficiency in Asia
Asia has one of the highest prevalence of vitamin A deficiency in the world, with the most clinical cases found there. Vitamin A deficiency is still considered a public-health problem in many countries of Asia and 33.5% of pre-school children have vitamin A deficiency.
The WHO Global Database on Vitamin A Deficiency reports that:
- In the Philippines, vitamin A deficiency affects approximately 1.7 million children (15.2%) aged 6 months to 5 years. Subclinical vitamin A deficiency affects one out of every ten pregnant women.
- In Bangladesh, one in every five children aged 6 months to 5 years is estimated to be vitamin A-deficient. Among pregnant women, 23.7% are affected by vitamin A deficiency.
- promotion of optimal breastfeeding practices;
- promotion of proper complementary feeding practices;
- nutrition education and consumption of a diversified diet that includes nutrient-rich fruits and vegetables and foods from animal sources;
- vitamin A capsule supplementation;
- food fortification; and
- other public health measures, including control of infectious diseases.
These approaches to vitamin A deficiency have had real successes, however, vitamin A deficiency remains a public health problem in many parts of the world. Target populations are sometimes missed with these interventions, especially in hard to reach areas.
If proven to be efficacious and improve vitamin A status, Golden Rice has the potential to be an intervention that could be used to complement these proven vitamin A deficiency control approaches.
Because rice is widely produced and consumed, Golden Rice has the potential to reach many people, including those who do not have reliable access to or cannot afford other sources of vitamin A.
Golden Rice is intended to be used in combination with existing approaches to overcome vitamin A deficiency, including eating foods that are naturally high in vitamin A or beta carotene, eating foods fortified with vitamin A, taking vitamin A supplements, and optimal breastfeeding practices.
The body converts beta carotene in Golden Rice to vitamin A as it is needed. According to research published in the American Journal of Clinical Nutrition in 2009, daily consumption of a very modest amount of Golden Rice – about a cup (or around 150 g uncooked weight) – could supply 50% of the Recommended Daily Allowance of vitamin A for an adult.