Vitamin A is a fat-soluble organic compound (a.k.a. Retinol). It contributes to health of eyes, teeth, soft tissues, mucous membranes and skeletal composition. It is also an essential element for the maintenance of the immune system and embryonic development.
Vitamin A is a component of retinol and carotene. Some of the richest sources of vitamin A are
- Polar bear liver (100,000 IU)
- Cod liver oil (30000 μg)
- Turkey liver (8058 μg)
- Pork, fish, beef liver (6500 μg 722%)
- Chicken liver (3296 μg)
Too much vitamin A and toxicity
Vitamin A is fat-soluble compound and therefore takes significantly longer than most vitamins to be excreted from the body. This contributes to more pronounced vitamin A toxicity if supplemented in higher doses overtime.
The toxic levels of the vitamin A accumulate with consumption at the levels as low as 12,000 IU per day. Excessive alcohol consumption facilitates an increased toxicity of vitamin A.
Side effects & dangers of too much vitamin A retention in the body
- Abnormal development of fetuses
- Osteoporosis and bone fragility resulting in spontaneous skeletal fractures
- Dehydration of the mucous membranes
- Gastrointestinal disturbances
- Development of pseudotumor cerebri syndrome
- Smoking and chronic alcohol consumption
- Older women are at increased risk of dying of cardiovascular disease or cancer associated with increased vitamin A toxicity
- Liver disorders
Symptoms of excessive vitamin A consumption and intoxication
- Nausea
- Drowsiness
- Irritability and anxiety
- Anorexia
- Blurry vision
- Hair loss
- Vomiting
- Muscle and abdominal pain
- Muscle weakness
- Reduced mental clarity and confusion
- Headaches
- Elevated basal temperature
- Fatigue
- Abnormal weight loss
- Anemia
- Liver damage [ref]
Considerations of vitamin A intoxication
Symptoms will begin to resolve after excessive vitamin A supplementation, alchohol consumption and smoking is stopped.
Water soluble forms of vitamin A may help to reduce potential toxicity as the vitamin A would be excreted at a greater rate from the body. However, water soluble forms of vitamin A are more potent when taken in the same armounts as non soluble compounds, therefore the doses have to be adjusted.
A properly balanced diet would contribute to more appropriate vitamin A levels unless additional supplementation is recommended by a nutritional specialist.