Vitamin A, also known as retinol or retinoic acid, is a fat-soluble vitamin that plays a crucial role in maintaining good health. Since your body can’t produce vitamin A on its own, it’s essential to get it from food sources or supplements.
There are two main forms of vitamin A:
- Preformed vitamin A: This form is already active and ready for use in the body. It’s typically found in animal-based foods.
- Carotenoids: These are compounds, like beta-carotene, that your body converts into vitamin A. Carotenoids are commonly found in fruits and vegetables.
Functions of Vitamin A
Vitamin A is widely known for supporting eye health, especially in low-light conditions. It also plays a key role in color perception. But that’s not all—vitamin A is vital for many other processes in the body, including:
- Stimulating the production and function of white blood cells, which are crucial for immune function.
- Supporting cell growth and development.
- Helping with bone remodeling.
- Keeping the endothelial cells, which line the blood vessels, healthy.
- Acting as an antioxidant to combat harmful free radicals in your body.
Causes of Vitamin A Deficiency
In developed countries, vitamin A deficiency is rare, especially for people with a balanced diet. However, certain conditions or life stages can increase the risk, such as:
- Preterm infants
- Pregnant or breastfeeding people in developing countries
- Malabsorption disorders, like Crohn’s disease, ulcerative colitis, cystic fibrosis, and celiac disease
Symptoms of Vitamin A Deficiency
Vitamin A deficiency can cause several health issues, including:
- Vision problems: One of the most notable symptoms is xerophthalmia, which causes difficulty seeing in low light. If untreated, it can lead to blindness.
- Skin issues: Dry, itchy skin or rashes are common.
- Fertility problems and delayed growth in children.
- Frequent respiratory infections.
Health Risks from Vitamin A Deficiency
If you notice symptoms of vitamin A deficiency, it’s important to get checked by a doctor. Blood tests can help measure your vitamin A levels. You can also use at-home test kits for this purpose. If you have low levels, your doctor may suggest dietary changes or vitamin A supplements. However, since vitamin A supplements can interact with certain medications, consult a healthcare provider before starting any new treatment.
Vitamin A Food Sources
Good news—there are plenty of foods rich in vitamin A. Some of the best sources include:
- Animal products like cheese, eggs, oily fish, yogurt, milk, and liver.
- Plant-based foods such as spinach, carrots, red bell peppers, sweet potatoes, mangoes, apricots, and papaya.
Topical retinol (a form of vitamin A) is also commonly used in skincare to help with aging, wrinkles, acne, and rough skin. However, it’s important to use sunscreen when applying retinol to avoid irritation.
Vitamin A Upper Intake Limits
Vitamin A intake is typically measured in retinol activity equivalents (RAE) or international units (IU). The recommended daily intake for vitamin A is:
- 900 mcg RAE (3,000 IU) for adult men.
- 700 mcg RAE (2,333 IU) for adult women.
The upper safe limit for vitamin A is around 3,000 mcg of preformed vitamin A per day. Exceeding this, especially over long periods, can cause issues.
Side Effects of Excess Vitamin A
Taking too much vitamin A can lead to several health problems. For example, even a single large dose may cause gastrointestinal discomfort, dizziness, and blurred vision. Long-term excessive intake can lead to:
- Bone thinning
- Liver damage
- Headaches
- Skin irritation
- Diarrhea
- Joint pain
- Birth defects (for pregnant individuals)
It’s crucial to maintain a balance and avoid over-supplementing with vitamin A to prevent these serious risks.
