Vitamin A is an essential fat-soluble vitamin. Vitamin A is also known as retinol, which is also an alcohol. There is a recommended daily allowance for both men and women. The recommended daily allowance for men is 900 micrograms or 3000 IU. The recommended daily allowance for women is 700 micrograms or 2300 IU. People should not consume more than 3,000 micrograms, or 10,000 IU.Vitamin A can be found in many of our daily foods naturally. Yellow and orange vegetables in particular contain the carotenoids that vitamin A is associated with. Each of the following foods contains at least 150 micrograms, or 500 IU.
- Broccoli leaves, florets have a lower amount
- Sweet potatoes
- Collard greens
- Winter squash
- Leafy vegetables
One of the most common deficiencies for vitamin A is night blindness and impaired vision. If the person is deficient for an extended amount of time, several issues can occur with the eyes including conjunctivitis and the erosion of the corneal surface. Additionally, people develop impaired immunity and hyperkeratosis. Hyperkeratosis is when white lumps develop at the base of the hair follicles. Other issues can occur within the lining of the urinary bladder and upper respiratory passages.Vitamin A deficiency is common in many third world countries. Many people die from diarrhea and measles in these countries and vitamin A has been shown to significantly reduce these deaths in these countries. When a person has an infected, the retinol levels in the blood reduce rapidly and inadequate quantities of vitamin A is often a contributing factor to people who died from an infectious disease. Because of its effect on the immune system, vitamin A is often referred to as an anti-infective vitamin.Several side effects can occur in a person if they greatly exceed the recommended daily allowance of vitamin A. Adults who consume 2 million IU of vitamin A will experience headache, drowsiness, nausea and vomiting. If they are chronically consuming 50,000 IU of vitamin A, adults will likely experience anorexia, loss of hair, bleeding lips, blurred vision, extreme fatigue, liver damage, muscle pain and stiffness and possibly injury to the brain. Although most people are not likely to consume this large amount of vitamin A, these side effects just go to show you that more is not necessarily better and this is true with the majority of other vitamins.