The ins and outs of Vitamin A

Open your eyes to the vital role vitamin A plays in maintaining everything from your immune function to healthy skin and your vision.

Did your parents ever tell you that eating your carrots would help you see in the dark? There is some substance to the claim.

Carrots are an excellent source of vitamin A, which does in fact play an important role in eye health – along with doing wonders for our skin, immune system, growth, fertility and organ function.

In fact, vitamin A is an all-rounder that plays an essential role in our health and wellbeing.

What is vitamin A and what does it do?

What doesn’t it do, might be the better question.

Community pharmacist and herbalist Gerald Quigley says vitamin A supports more than 120 essential functions, ranging from thyroid function, to vision, reproduction health and even brain function.

It also plays an important role in our mucus.

“It’s very important for mucus surfaces, because that is a barrier to infection and we have mucus surfaces in our mouth, our gut and our bowel and they have to be maintained to be flexible and resilient,” Gerald says.

And a recent study by Brown University revealed a diet high in vitamin A could reduce the risk of the second-most common type of skin cancer by as much as 17 per cent compared with those who had a low daily dosage of the vitamin.

How much vitamin A do you need?

The recommended intake of vitamin A depends on your age, though is generally around 900mcg a day for men, and 700mcg for women.

Pregnant and breastfeeding women may require more.

Check with your GP to determine how much you need.

What if you don’t get enough vitamin A?

While vitamin A deficiency is rare, Gerald says you may become vitamin A deficient if your body has trouble absorbing the nutrient from your food.

“This can be the result of a prolonged dietary deficiency, or if the body’s storage or transport of vitamin A is reduced, or if carotene (from which vitamin A in the diet is obtained) is not adequately converted to vitamin A,” he says.

“Signs of vitamin A deficiency include night-blindness, which can progress to complete blindness if not treated, very dry and hard skin surfaces, poor dental health, poor immune function, reduced reproductive capabilities.”

Gerald says for teenagers, a common symptom of vitamin A deficiency is acne. While for adults signs can range from dry hair or skin, brittle nails, sinus problems, poor sense of taste and smell, reduced tear production, poor immune function and eye diseases like ulcers on the cornea.

Vitamin A deficiency can be diagnosed by a blood test and treated through supplementation.

Gerald recommends that anyone who thinks they may be low in vitamin A, or any other nutrients, seek professional advice from a pharmacist or clinical naturopath.

Risks of too much vitamin A

It is possible to have too much vitamin A.

Gerald says this can occur if our body does not dispose of or break down vitamin A well.

“Symptoms include bone and joint pain, malaise, vomiting, dry rough skin, coarse and sparse hair, alopecia of the eyebrows, and dryness of mucous membranes,” he explains.

However vitamin A overdose is rare.

“In our society this is not common at all,” Gerald says. “We’re talking about 100,000 units a day long-term, which is a phenomenally high dose.”

vitamin a

Sources of Vitamin A

Gerald says vitamin A refers to a family of fat-soluble compounds, of which there are two types.

The first type is preformed, found in meat, poultry, fish and dairy products, while the second type, known as precursor or provitamin A, is found in fruits, vegetables and plant products.

The most common type of precursor vitamin A is beta carotene.

Dietitian Jane Freeman, of the Dietitians Association of Australia, says orange and yellow vegetables are the best sources – this means topping up on carrots, sweet potato and pumpkin.

Good food sources of fully formed and precursor vitamin A include:

  • Liver
  • Fish oils
  • Milk
  • Eggs
  • Leafy green vegetables
  • Tomatoes
  • Fruits
  • Tofu
  • Lean meat
  • Chicken
  • Wholegrain foods like rice, cereals, bread, pasta, couscous, oats, plenta and barley

Be aware that cooking can remove beta carotene.

“When you heat green and yellow vegetables which have beta carotene, 15-35 per cent of it is lost, so salads are a great option,” says Gerald.

Written by Samantha Alleman and Alana Schetzer.