Ask the experts: Vitamin A

Q: "I have read that vitamin A is good for eyesight, acne and our immune systems. I have also read that too much vitamin A is not good for our bodies. Could you explain if it's beneficial to take vitamin A supplements?"

Jenna

A: Michelle Gibbs, a postgraduate nutrition student at the Department of Human Nutrition, University of Otago, responds:

"You're right on both counts: vitamin A is necessary for your eyesight and immune system but can also be damaging if taken in excess, ie. more than 3000 micrograms a day.

High doses of vitamin A can lead to headaches, liver and skin problems, damage to your eyesight, and cause a great deal of harm to your unborn child. In the case of vitamin A, too much of a good thing really can go terribly wrong. Vitamin A supplements have even been linked to an increased rate of death.

But it isn't all bad news. We only need around 700 micrograms a day, and the good news is you are bound to already get enough from your diet. Vitamin A can be found in both animal and plant products. Liver, dairy products, fish oils and eggs are great sources. Vitamin A is also found in orange and yellow vegetables and fruit and green leafy vegetables.

So the bottom line is if you think you could have a deficiency, or you want acne treatment, go to your doctor for advice. The dangers of unnecessarily supplementing your diet with vitamin A aren't worth it."