Vitamin A Deficiency
Article Highlights
- Vitamin A stores in most individuals are enough to last one year before signs of vitamin A deficiency develop.
- Vitamin A deficiency may show up as night blindness or as one or more of many other signs and symptoms.
The amount of vitamin A stored in most individuals is enough to last for at least one year before experiencing any signs of vitamin A deficiency. Vitamin A levels may be measured in the blood (lower limit of normal = 20mcg/dl). Signs of deficiency include:
- Night blindness (usually an early manifestation).
- Dry, scaly, occasionally cracked skin and obstruction of hair follicles; slow wound healing.
- Dry mucous membranes, especially the cornea, which may lead to scarring and blindness. Vitamin A deficiency is the leading cause of blindness worldwide.
- Decrease in growth, including skeletal growth.
- Impaired reproduction (male and female).
- Chronic diarrhea.
- Increased susceptibility to infections, especially the respiratory tract but also the eyes, kidneys and skin.
- Kidney stones.
- Impairment of hearing, taste and smell.
- Nerve damage and gait disturbance.
- Reduced ability to perspire.