Vitamins and Vitamin Safety

We hear a lot about vitamins and minerals, our cereals are fortified with them and health food shop shelves are groaning with tubs of them in varying quantities and strengths. But are they actually beneficial? And can they ever be dangerous?

Vitamins are vital for your health. Some can be manufactured by the body, such as vitamin D which just needs a little sunlight to encourage production. Our bodies use them to stay healthy, support bodily functions and prevent disease.

Deficiencies in key vitamins are bad news - for example if you don't get enough vitamin C in your diet, you could develop scurvy and end up with bleeding gums, weakness and bleeding under your skin.

Which Vitamins are Absolutely Essential?

The most important vitamins to include in your diet are:

• vitamin A
• vitamin B1 (known as thiamin)
• vitamin B2 (known as riboflavin)
• vitamin B3 (known as niacin)
• vitamin B6 and B12
• vitamin C
• vitamin D
• vitamin E
• vitamin K

There are other 'vitamins' that you might read about online which are said to have miracle properties such as the ability to cure cancer - for example 'vitamin B17'. Actually, B17 isn't a vitamin at all, but a partly synthetic form of a substance called amygdalin. It's often called vitamin B17.

How Can I Take Vitamins?

There are almost as many different ways to take vitamin supplements as there are vitamins! Usually they are available in pills, tablets, and capsule form, but some are also sold as a liquid supplement. They are called supplements for a good reason - over the counter vitamin preparations are supposed to increase the amounts in your food, not replace a healthy diet.

Look for:

• Established brands. The best names have been around for years. Ask someone in the shop for advice on ranges.
• Mystery ingredients - some manufacturers use "fillers" like magnesium stearate, which can compromise the effectiveness of the nutrients in the supplement.
• Recommendations for use. Are the instructions clear about how often and when to take the supplements?
• Amount per serving and % RDA - this is important as some vitamins, like vitamin A, can be toxic at very high doses.
• Additives - is the product free from potential allergens, like wheat or milk?
• Expiry date.
• Storage instructions.

So, Can They Be Dangerous?

Generally, if you're pregnant, breast feeding or suffering with diabetes, high blood pressure or heart problems, you should probably avoid supplementing with vitamins, but otherwise, there's no danger to taking vitamins unless you mega-dose or take excessive amounts, especially the fat-soluble vitamins like A, D, E and K.

Reported problems of overdosing on vitamin A are:

• nausea and vomiting
• headaches, dizziness and blurred vision
• potential birth defects
• liver problems
• higher risk of osteoporosis

Similarly, if you take too much vitamin D, you could end up with:

• nausea and vomiting
• loss of appetite
• constipation
• weakness
• weight loss
• heart rhythm problems

If you overdo some vitamins you could end up with side effects, and too many can interfere with some medical tests or interact with prescribed medication. If you are on any medication, ask your GP before taking supplements.

As a general rule, if you keep to the specified maximum doses of vitamins which should be printed on the label, and if you use vitamin supplements to boost rather than replace natural vitamins from your diet, taking vitamins shouldn't be at all harmful.