Australia's vitamin industry is worth around a billion dollars a year.

That's not surprising, when you consider 80 per cent of us take vitamins or supplements regularly.

But could vitamins be doing us more harm than good?

And how do you know which ones to take?

Professor Kerryn Phelps joined us this morning to share a wealth of information on vitamins.

• If your child eats a balanced diet, that is plenty of fresh fruit and vegetables, red meat, fish, chicken then there’s no reason why they should be taking vitamin supplements
• But if your child frequently has infections, lacks energy, doesn’t eat meat, fish or vegetables regularly, or they’re overall picky eaters, then you can consider giving them a child’s multivitamin, fish oil, and possibly iron
• Teenagers also might fall into this, again picky eaters, a diet that’s lacking, and teenagers who do a lot of sport and exercise may need a multivitamin, including one which contains iron and fish oil
• Adolescent girls need protein and iron

• Calcium
• Iron
• Omega 3
• If you’re planning a pregnancy or are pregnant you need to take: Folate, vitamin d, omega 3, iodine,
• In general, women will benefit from calcium, iron, fish oil.

• Zinc
• Multivitamin
• Selenium
• Vitamin D
• Magnesium
• Fish Oil

• Multivitamin
• CoQ10
• Fish Oil
• Vitamin D
• Calcium (not mentioned on video)
• Magnesium (not mentioned on video)
• Zinc (not mentioned on video)

• Iron
• Vitamin B 12
• Zinc
• Protein

• Vitamin A, Copper - if you’re pregnant
• Iron – if you have haemochromatosis (iron overload)
• Calcium – if you’re at risk of prostrate cancer
• Iodine – if you have acne, Thyroiditis
• Some vitamins can be harmful with prescription medication/ with surgery