In my last few articles I have been talking about vitamins. Today I am going to be discussing in greater detail the vitamin at the beginning of the alphabet – Vitamin A.
Vitamin A was the first vitamin discovered hence it being given the the first letter of the alphabet. It was officially discovered between 1912 and 1914 by Elmer McCollum and M. Davis, although in 1913 Thomas Osborne and Lafayette Mendel found that butter contained a fat soluble nutrient that would soon become known as vitamin A.
Vitamin A is a fat soluble vitamin and its most notable function is that it helps improve vision, particularly night vision. In fact the Egyptians inadvertently discovered that vitamin A could help assist with night vision when they used liver (a rich source of vitamin A) to cure night blindness (a condition where it is difficult or impossible to see in low light). However, it also performs a number of other important functions in your body which include:
– Acting as an antioxidant (a substance that protects the body’s cells from dangerous free radicals).
– Assisting in normal growth (particularly proper development of the bones and teeth).
– Assisting in normal reproduction (vitamin A is thought to be vital in the production of sperm and for healthy fetal growth).
– Helping your eyes, skin and mucus lining to stay moist.
– Possible protection against cancer and other diseases (according to How Stuff Works).
– Strengthening the immune system.
Vitamin A can be sourced from both animals (in the form of retinol) and plants (in the form of carotenoids). It is recommended that men consume 0.7mg of vitamin A per day whilst women should consume 0.6mg daily. The richest source of vitamin A is liver but experts advise that you limit your consumption of this meat to a maximum of twice per month. Dairy products such as egg, cheese, milk and butter are also great sources of vitamin A. If you want to get your vitamin A from vegetables then carrots, peas and spinach are all good sources.
Not getting enough vitamin A can lead to problems with your vision, hence the rumours that eating carrots can improve your eyesight. If you notice problems with your night vision or struggle to see in the dark then this could be an early indicator of vitamin A deficiency which if left untreated can develop into full blindness. Vitamin A deficiency can also cause the skin to become dry and make the body more susceptible to infection.
However, you also need to make sure that you are not getting too much vitamin A. Overdosing can have a significant impact on your bones leading to both osteoporosis (reduced bone density) and an increased risk of bone fractures as you age. It can also lead to hair loss, diarrhea, dry skin and stunted growth.
Overall, you should be able to get plenty of vitamin A from your diet, provided it contains some dairy products and leafy green vegetables. Given the fact that your body can store excess vitamin A for later use and that high levels of this mineral are toxic there should be no reason for you to use specific vitamin A supplements. However, if you feel that you really do need to take a supplement make sure that the supplement you choose is not too concentrated and most importantly…don’t overdo it.
Toxicity of Vitamins Information (Medical News Today)
Vitamin A Information (Food Standards Agency)
Vitamin A Information (How Stuff Works)
Vitamin A Information (Life Clinic)
Vitamin A Information (Wikipedia)