The body need vitamin A, which is vital for growth and development. It is essential for immune system performance, eyesight, reproduction, and cell recognition.
➥What is Vitamin A?
Vitamin A, also called retinol, has many functions in the body. In addition to helping the eyes adjust to light changes, vitamin A plays an important role in bone growth, tooth development, reproduction, cell division, gene expression, and regulation of the immune system. The skin, eyes, and mucous membranes of the mouth, nose, throat and lungs depend on vitamin A to remain moist. Vitamin A is also an important antioxidant that may play a role in the prevention of certain cancers.
Vitamin A, also known as retinol, has several important functions.
These include:
- helping your body's natural defence against illness and infection (the immune system) work properly
- helping vision in dim light
- keeping skin and the lining of some parts of the body, such as the nose, healthy
➥How to get more vitamin A
It’s recommended that men get 900 micrograms (mcg) of vitamin A per day and women get 700 micrograms. You can get your fill by eating plenty of red, orange, or yellow veggies, along with some animal products.
Some of the top sources are:
- sweet potato (1,403 mcg in one medium sweet potato)
- carrots (459 mcg in 1/2 cup raw)
- milk with added vitamin A (149 mcg in 1 cup)
- cantaloupe (135 mcg in 1/2 cup)
- red bell pepper (117 mcg in 1/2 cup)
- dried apricots (63 mcg in 10 halves)
- eggs (75 mcg in one large egg)
- salmon (59 mcg in 3 ounces)
- plain yogurt (32 mcg in 1 cup)
- canned light tuna (20 mcg in 3 ounces)
Pro tip: Your body can only absorb vitamin A when you eat it with fat. So if your A source doesn’t have much fat on its own (like in the case of raw fruits or veggies), pair it with a higher fat food like olive oil, avocado, or nuts.
➥WHAT ARE THE BENEFITS OF VITAMIN A?
•Reduced risk of blindness
An age-related eye disease study by the National Eye Institute found that taking high levels of antioxidants, such as vitamin A, along with zinc, might reduce the risk of developing advanced age-related macular degeneration by as much as 25%. Age-related macular degeneration is the most common cause of loss of vision in the older population.
•Reduced acne and sun damage
Vitamin A helps to promote and maintain a healthy dermis and epidermis – the top two layers of the skin. When applied topically, there’s evidence that retinoids (a class of compounds derived from vitamin A) can be used to treat acne and certain signs of sun damage, known as photo aging.
However, a commonly experienced side effect of topical application of retinoids is ‘retinoid dermatitis’, which can lead to skin irritation and scarring, but adjusting the dose can reduce adverse skin reactions.
•Stronger teeth and bones
Vitamin A helps your body absorb calcium so it’s important for oral and bone health. It strengthens tooth enamel and promotes the healthy mucous in the mouth that coats cheeks and gums, making it less susceptible to infection and disease.
It’s also important for healthy bones. Both osteoblasts (bone building cells) and osteoclasts (bone breaking down cells) need vitamin A, but clinical research has found that higher vitamin A levels are linked to lower bone density and fractures.
➥Recommended intake
The recommended intake of vitamin A varies according to age. People also need more during pregnancy and while breastfeeding.
It is available in several forms, and the vitamin A content in foods is often measured as retinol activity equivalents (RAEs).
One RAE is equal to:
- 1 microgram (mcg) of retinol
- 12 mcg of beta-carotene from food
- 2 mcg of beta-carotene from supplements
- 3.33 international units of vitamin A
The recommended daily allowancesTrusted Source of vitamin A by age are as follows:
- up to 6 months: 400 mcg
- 7–12 months: 500 mcg
- 1–3 years: 300 mcg
- 4–8 years: 400 mcg
- 9–13 years: 600 mcg
- 14+ years: 900 mcg for males and 700 mcg for females
During pregnancy, the requirement is 770 mcg per day. While breastfeeding, it is 1,300 mcg per day.
The 2007–2008 National Health and Nutrition Examination Survey found that the average U.S. individual, aged 2 years and above, consumes 607 mcg of vitamin A per day.
➥What happens if you take too much vitamin A?
“Our bodies are clever, meaning you’ll only convert as much beta-carotene into retinol as you need,” says Denby. “Not only this, but your body is able to store any vitamin A that it doesn’t need right away for later use, because vitamin A is fat soluble. However, it's still important not to go absolutely crazy.
“Even though your body can store vitamin A, prolonged periods of excess vitamin A can have adverse effects on bone health, and increase the risk of osteoporosis.”
Other signs of excessive vitamin A intake include nausea, headaches, dizziness, blurred vision and fatigue.
“Long-term high intakes of beta-carotene may lead to your skin gaining a yellow-orange tint. This can easily be reversed by reducing your beta-carotene intake,” adds Denby.
If you’re pregnant, large amounts of vitamin A can harm your unborn baby so it’s best to avoid eating liver or liver products such as pate, as they are very high in the vitamin.
“Vitamin A is teratogenic, “This means excessive intakes increase the risk of birth defects. Speak to your midwife or health professional if you’re concerned.”
