Vitamin A

Function

Vitamin A is necessary for night vision. Promotes normal growth, healthy teeth, skin, nails. Important for the immune system, surface tissues especially those which excrete mucus e.g. intestines, lungs and vagina. Prevents poisoning, infections and allergic reactions.

Vitamin A deficiency

Night blindness, oversensitive to light, eye catarrh, skin problems, dandruff, fragile nails, increased susceptible to infections, poor growth

Vitamin A food sources

Fish liver oils, liver, dark green leafy vegetables, carrots, pumpkin, dairy products

Examples of therapeutic usage (not always proven effective or safe)

Inflammations, allergies, eczema, acne, blackheads, boils, swollen glands, polyps

Toxic dose – symptoms

Nauseous, vomiting, reduced appetite, irritation, headache, sore arms and legs, nosebleeds, dizziness, discolored red gums. The symptoms will disappear as you stop taking the vitamin. If you suffer from liver disease, hyperlipidemia or severe protein malnutrition or if your alcohol intake is high, you may be distinctly susceptible to the adverse effects.

Vitamin A is fat soluble. This means that the body will not be able to get rid of the excess through urine, like water soluble vitamins. Because fat-soluble vitamins are stored for long periods, they generally pose a greater risk for toxicity than water-soluble vitamins when consumed in excess. This applies if you take high doses of vitamin supplements. Eating a normal and well-balanced diet will not lead to toxicity in otherwise healthy individuals.

Vitamin A: AIs (Adequate Intakes)

Vitamin A: RDAs (Recommended Dietary Allowances)

Beta-carotene supplements are advised only to serve as a pro-vitamin A source for individuals at risk of vitamin A deficiency.

Source: USDA Dietary Reference Intakes