Vitamin A deficiency
Vitamin A is essential for maintaining healthy vision, skin, immune function and reproduction. It is found in two forms: retinol (from animal sources such as liver, eggs and dairy) and beta-carotene (from plant sources such as carrots, sweet potatoes and spinach).
Vitamin A deficiency is uncommon in the UK but can occur in people with conditions that impair fat absorption, such as coeliac disease, Crohn's disease and chronic liver disease.
Symptoms of deficiency include difficulty seeing in dim light (night blindness), dry skin, increased susceptibility to infections and, in severe cases, damage to the cornea.
A blood test for vitamin A measures retinol levels. Both deficiency and excess can cause health problems, so testing is useful when there is clinical suspicion of either.
Causes of Vitamin A deficiency
Vitamin A deficiency results from inadequate intake or impaired absorption of the vitamin.
Causes include:
- Malabsorption conditions such as coeliac disease, Crohn's disease, chronic pancreatitis and cystic fibrosis, as vitamin A is fat-soluble and requires adequate fat absorption
- Chronic liver disease, which impairs vitamin A storage and metabolism
- Dietary insufficiency, which is rare in the UK but common in low-income countries where diets lack animal products and beta-carotene-rich vegetables
- Excessive alcohol use, which depletes liver stores and impairs metabolism
Vitamin A excess (hypervitaminosis A) can occur from excessive supplementation and causes symptoms including nausea, headaches, skin changes and, in pregnancy, birth defects. Pregnant women are advised not to take vitamin A supplements or eat liver.
Tests that can help check this condition
Learn more on the official NHS page .
