Can you take too many vitamins and minerals? - Yahoo! Lifestyle UK

Can you take too many vitamins and minerals?
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If you are taking large doses of vitamins or minerals, your doctor should be closely monitoring you. The fat-soluble vitamins - vitamins A, D, E, and K - are stored in the liver, and if they are taken in excess may build up to harmful levels more quickly compared to the water-soluble vitamins - the B vitamins and vitamin C (see Vitamin and mineral supplements).

If you do take a supplement, select a sensible one with the levels of nutrients recognized as safe and avoid going over the upper safe level.

Too many vitamins

Some vitamins can be harmful if taken in excess:

• Too much vitamin A can lead to headaches, blurred vision, cracked lips, and dry and rough skin.
• An excess of vitamin D can cause a poor appetite, nausea, and vomiting, plus deposits of calcium in body tissues.
• Large doses of the B-complex vitamins can produce symptoms ranging from itching, flushing, nausea, lightheadedness, and tingling sensations in the fingers, to progressive loss of balance and sensation in the legs.
• Excessive doses of vitamin C can cause diarrhoea and have also been reported to predispose those people susceptible to oxalate kidney stones (see Disorders of the urinary system). Symptoms usually disappear when the offending vitamin is withdrawn.

Too many minerals

• In children, excessive intake of iron is dangerous and too much fluoride turns the teeth brown.
• People being treated for ulcers may develop milk-alkali syndrome, due to excessive intake of calcium from medication, causing muscle pain and weakness.
• Excessive intake of vitamin D can cause overabsorption of calcium.
• Excessive zinc may suppress the immune system and interfere with the absorption of copper.

Upper safe level (USL)

This indicates the maximum safe amount of a nutrient to eat or take as a supplement without risk of side effects from poisoning. It is often divided into limits for long-term and short-term use.

In the Vitamin chart and Mineral chart, the upper safe level (USL) for long-term use is given for the supplements.

Lisa Hark, PhD RD & Dr Darwin Deen

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