Vitamin A is usually associated with good vision and especially night vision. As a child I was always told to 'eat my carrots so I could see in the dark'. While it is true that vitamin A is vital for vision, it also has a multitude of beneficial functions throughout the body. However, it is not true to list carrots as a source of this essential vitamin. The biologically active form of vitamin A is called retinol, because it is so prevalent in the retina of the eye. Carrots and other brightly coloured vegetables contain no vitamin A. They contain a pre-cursor to retinol known as carotene or beta-carotene, which has to be converted to the active form before it can do it's work. This conversion is never very efficient and quite difficult for some people. Genetic variations, too much fibre in the diet, a lack of bile salts and eating raw vegetables can all play their part in making the transition from carotene to retinol more difficult. Healthy individuals without these problems convert beta-carotene to retinol at a ration of about 6:1, which means they need to eat 6 molecules of beta-carotene to absorb one molecule of true vitamin A.
A study from Newcastle University on a group of women showed that 47% of them had a gene variant that made it difficult or impossible to convert beta-carotene into active vitamin A. It is easy, therefore, for some people to become deficient if they do not consume retinol in their food.
The only dietary sources of the active form of vitamin A are found in animal foods. Liver and eggs are the most abundant, (which is one of the reasons we have meal suggestions for these in our recipes section). Vitamin A gets very little attention compared to vitamins C and D, which is unfortunate because it is absolutely vital for our health and for the proper development of babies and children. It has such a profound effect on our health because it regulates the action of over five hundred genes in the body, which makes it a major controller of all of our cells and how they function.
Long before we knew what vitamin A is, ancient people from around the world were aware that eating liver could prevent or reverse blindness. The Egyptians described it at least 3500 years ago: Assyrian texts dating from 700 BC and Chinese medical writings from the 7th century AD both call for the use of liver in the treatment of night blindness. It has also been written about in 18th-century Russia and among the inhabitants of Newfoundland in 1929. 2,400 years ago, Hippocrates prescribed liver for blindness in malnourished children. Despite all this knowledge, vitamin A deficiency is still the leading cause of blindness in some parts of the world. It is extraordinary that all this ancient knowledge is ignored and the NHS recommends that pregnant mothers should avoid eating liver in case they consume toxic levels. (More about this later.)
Vitamin A helps to prevent us from becoming ill; it keeps our immune system from overreacting; it is necessary for growth and reproduction. We need vitamin A for building bones and teeth, and for the actions of our hormones. It is essential for the development of a foetus into a perfectly formed human baby. These are major roles, which are vitally important for our health.
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