Well known as the vitamin that helps you see in the dark, it does do this but an excess to help you see better is a fallacy. A deficiency can cause night blindness. Vitamin A is an antioxidant and a shortage can lead to certain types of cancer. Vitamin A may help protect against heart disease it is necessary for sexual function and helps to fight infection. It also helps the formation of bones and teeth, helps keep skin and hair healthy.
It’s found in some foods from animals e.g. liver, eggs and butter are very rich source, however there are two problems with these sources they are often very rich in fat, which can block your arteries, lead to the development of heart disease and cancer. Some of the animal products are so rich in Vitamin A they can be dangerous and you can overdose.
Most of the Vitamin A that you need can be obtained from plant foods—carrots and other red and yellow vegetables, dark green leafy vegetables are another excellent source of beta-carotene the precursor to Vitamin A. you can get plentiful amounts of beta-carotene from carrots, broccoli, chicory, spinach, endives, lettuce, apricots, elderberries and mangoes.
Other useful suppliers of Vitamin A are sweet potatoes, pumpkin, peas, kale, peppers, melons, cabbage, peaches, asparagus, watermelon, tomatoes, parsley and avocado. You don’t need to worry much about a deficiency of Vitamin A as the average person has enough stored in their liver to last about two years. But you should keep eating a wide variety of foods to ensure that you do not run out.
Deficiency: can be a cause of night blindness, lack of tear secretion, changes in the eyes and eventual blindness if deficiency is severe and untreated, respiratory infections, dry skin, changes in the mucus membranes, weight loss, poor bone structure, weak tooth enamel, diarrhoea and slow growth.
Overdose: Retinal—the animal form of vitamin A—can be harmful, and cause liver and bone damage. Anorexia, drowsiness, irritability, hair loss, headaches and skin problems are some of the symptoms.
Excessive consumption during pregnancy has been linked to birth defects. Children are more sensitive and are more likely to develop toxicity at high doses. Oral contraception may increase concentration.