Vitamin A

Vitamin A is a fat-soluble vitamin that is stored in the liver and fatty tissue. An adult body may store up to a year’s worth of vitamin A. As the body is not able to produce vitamin A, it must be obtained from food. In animal products, vitamin A occurs as retinoids, and in vegetable products as carotenoids. The liver transforms carotenoids into retinoids.

Vitamin A is important for people’s eyesight as it is needed in the production of photoreceptor cells in the retina. Moreover, vitamin A is important for skin growth, bone formation and foetal development. It also acts as an antioxidant, reducing the amount of infections.

Foods rich in vitamin A in retinoid form include liver, fatty dairy products, eggs ad cooking fats. High concentrations of carotenoids, in turn, can be found in orange and red vegetables, berries, fruit and dark leafy greens.

When should vitamin A levels be measured?

Vitamin A levels may decrease if the absorption of fat from the intestines is disrupted due to an inflammatory gastrointestinal illness (Crohn's disease), for example, or because part of the small intestine has been removed in surgery. Disruptions in liver and pancreatic functions may also affect absorption.

Symptoms indicating a vitamin A deficiency include:

• night blindness
• dry eyes
• dry skin and hair
• small cuts and sores
• damage in the cornea
• recurring infections
• anaemia.

The test can also be used to measure excessive intake of vitamin A from nutritional preparations, for example.

What does a vitamin A test measure?

A vitamin A test can be used to examine vitamin A levels in blood.