Like most other vitamins and minerals, vitamin A, or retinol, plays an important role in growth and development. However, monitor your vitamin A intake closely if you take supplements or eat a diet high in vitamin A foods, because overdoses can be harmful. According to AskDrSears.com, vitamin A is the only vitamin that can be consumed excessively from food sources.
Vitamin A Toxicity
Excessive vitamin iA ntake is also known as hypervitaminosis A. It can be either acute or chronic. Acute hypervitaminosis A results from taking too much vitamin A over a short time frame. Chronic vitamin A overdose may result in chronic hypervitaminosis A. Excessive intake of vitamin A is defined as 10 times the Recommended Daily Allowance, or RDA, which is 900 mcg for adult males or 700 mcg for women. RDA is slightly higher for pregnant and breastfeeding women.
Dietary Sources
Although hypervitaminosis A can be caused by excessive dietary intake, it is usually related to supplement overdose, according to the University of Maryland Medical Center. However, theoretically you could consume too much vitamin A from food sources, which would result in hypervitaminosis A. Examples of dietary sources of vitamin A include liver, carrots, sweet potato, pumpkin, apricots, green leafy vegetables, mango, cantaloupe and tuna. Some foods, such as breakfast cereals, are fortified with vitamin A.
Symptoms
Hypervitaminosis A causes a variety of symptoms, such as vomiting, diarrhea, loss of appetite, tiredness, headaches and dizziness. Sufferers may experience poor muscle coordination, itchiness and scaling of the skin, bone pain, hair loss, irregular menstruation in women, osteoporosis, and temporary or permanent liver damage, as noted by the American Cancer Society. These symptoms are most often related to vitamin A overdose from supplements. During pregnancy, hypervitaminosis A may cause serious birth defects. If you are a smoker, drink alcohol regularly or have a liver disorder, be especially careful to limit vitamin A intake to the RDA.
Beta Carotene
It is safe and effective to obtain your vitamin A from a diet rich in beta carotene, according to AskDrSears.com. Unlike vitamin A supplements, which deposit pure vitamin A directly into the body, beta carotene is transformed into vitamin A after consumption. However, the body only converts as much beta carotene as it needs, which results in a lower risk of hypervitaminosis A. Beta carotene is responsible for the orange color of vegetables like carrots, sweet potatoes, cantaloupe and apricots, and is also found in leafy green vegetables.
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