Friday, 22 October 2010

Safe Upper Levels for Vitamins, Minerals & Micronutrients

Most people should be able to get all the nutrients they need by eating a varied and balanced diet. But if you choose to take supplements, it's important to know that taking too much or taking them for too long can cause harmful effects.

So if you choose to take supplements, make sure you're informed.

The advice given in this section is aimed at adults. You might also want to check out the information in the 'Ages and stages' section, which has nutrition advice for all ages and includes advice on what foods to avoid for women who are pregnant or trying for a baby.

Use the menu on the right hand side to go to a vitamin, mineral or trace element.

What are vitamins?

Vitamins are essential nutrients that your body needs in small amounts to work properly. There are two types of vitamins: fat-soluble and water-soluble.

Fat-soluble vitamins
Fat-soluble vitamins are found mainly in fatty foods such as animal fats (including butter and lard), vegetable oils, dairy foods, liver and oily fish.

Your body needs these vitamins every day to work properly. However, you don't need to eat foods containing them every day.

This is because, if your body doesn't need these vitamins immediately, it stores them in your liver and fatty tissues for future use. This means the stores can build up so they are there when you need them. But, if you have much more than you need, fat-soluble vitamins can be harmful.

These are all fat-soluble vitamins:
  • vitamin A
  • vitamin D
  • vitamin E
  • vitamin K
Water-soluble vitamins
Water-soluble vitamins are not stored in the body, so you need to have them more frequently.

If you have more than you need, your body gets rid of the extra vitamins when you urinate. Because the body doesn't store water-soluble vitamins, generally these vitamins aren't harmful.

Water-soluble vitamins are found in fruit, vegetables and grains. But unlike fat-soluble vitamins, they can be destroyed by heat or by being exposed to the air. They can also be lost in the water used for cooking.

This means that by cooking food, especially boiling, we lose lots of these vitamins from the food we eat. The best way to keep as much of the water-soluble vitamins as possible is to steam or grill, rather than boil.

These are all water-soluble vitamins:
  • vitamin B6
  • vitamin B12
  • vitamin C
  • biotin
  • folic acid
  • niacin
  • pantothenic acid
  • riboflavin
  • thiamin

What are minerals?

Minerals are essential nutrients that your body needs in small amounts to work properly. We need them in the form they are found in food.

Minerals can be found in varying amounts in a variety of foods such as meat, cereals (including cereal products such as bread), fish, milk and dairy foods, vegetables, fruit (especially dried fruit) and nuts.

Minerals are necessary for three main reasons:
  • building strong bones and teeth
  • controlling body fluids inside and outside cells
  • turning the food we eat into energy
These are all essential minerals:
  • calcium
  • iron
  • magnesium
  • phosphorus
  • potassium
  • sodium
  • sulphur

What are trace elements?

Trace elements are also essential nutrients that your body needs to work properly, but in much smaller amounts than vitamins and minerals.

Trace elements are found in small amounts in a variety of foods such as meat, fish, cereals, milk and dairy foods, vegetables and nuts.

These are all trace elements:
  • boron
  • cobalt
  • copper
  • chromium
  • fluoride
  • iodine
  • manganese
  • molybdenum
  • selenium
  • silicon
  • zinc

Safe Upper Levels for Vitamins and Minerals, May 2003 by the Expert Group on Vitamins and Minerals, 350 page report (pdf, 1MB) source:  via via

The data were adequate to establish Safe Upper Limits for vitamin B6 (page 81) ß-carotene (page 127),
vitamin E (page 145), boron (page 164), copper (page 187), selenium (page 232), zinc (page 253)
and silicon (page 306).

Guidance was given for biotin (page 36), folic acid (page 42), niacin
(page 52), pantothenic acid (page 62), riboflavin (page 68), thiamin (page 74), vitamin B12 (page 93),
vitamin C (page 100), vitamin A (page 110), vitamin D (page 136), vitamin K (page 154), chromium
(page 172), cobalt (page 180), iodine (page 203), manganese (page 213), molybdenum (page 219),
nickel (page 225), tin (page 240), calcium (page 264), iron (page 275), magnesium (page 287),
phosphorus (page 293) and potassium (page 299).

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