How do vitamins and minerals work

Home Healthy eating. Vitamin and mineral supplements. Actions for this page Listen Print. Summary Read the full fact sheet.

On this page. Vitamins and minerals are obtained from food Vitamin and mineral deficiencies Vitamin pills are not miracle cures Vitamin use and cancer claims Vitamin and mineral supplements can be dangerous Vitamin and mineral supplements are a short-term measure Seek professional advice when taking vitamin and mineral supplements Where to get help.

Vitamins and minerals are obtained from food Research indicates that most of the vitamins you get from the food you eat are better than those contained in pills. Vitamin and mineral deficiencies Our body only needs a small amount of vitamins and minerals every day. However, some people may need supplements to correct vitamin or mineral deficiencies and this includes: pregnant women and women who are breastfeeding people who smoke, drink alcohol in excess or use illegal drugs crash dieters or those on very strict diets the elderly especially those who are disabled or chronically ill some vegetarians or vegans women with heavy periods people with food allergies those with malabsorption problems such as diarrhoea, coeliac disease, cystic fibrosis or pancreatitis.

Folate and pregnancy Women who are pregnant or planning a pregnancy are recommended folic acid also known as folate supplements to reduce their risk of having a child with a neural tube defect, such as spina bifida. Vegan diets and vitamin supplements Also, people who follow vegan diets, especially if pregnant, may benefit from vitamin B12 supplements.

Vitamin pills are not miracle cures It is commonly believed that taking mega-doses of certain vitamins will act like medicine to cure or prevent certain ailments. Stress, tiredness and vitamin pills Vitamin supplements are commonly considered to be an antidote to stress. Anti-ageing vitamins Vitamin E is often singled out as the potential fountain of youth. Vitamin use and cancer claims Some claims have been made that certain vitamins can treat different cancers.

For example: Vitamin A beta-carotene in large doses does not cure cancer and can be toxic, particularly if taken as pills rather than food. Studies have linked vitamin A to an increase in other cancers — such as lung cancer in smokers, if taken in supplement form. Although there is some evidence vitamin E could play a small role in preventing some cancers equally, there is evidence that it could speed up the onset of other types of cancer.

However, this has not been proved or disproved. High doses of antioxidants are unlikely to help with the effectiveness of conventional cancer treatments such as chemotherapy and radiotherapy. In fact, megadoses of antioxidants can interfere with some medical treatments for cancer by helping to protect the cancer cells that the therapies aim to destroy.

Some studies have shown prostate, breast and lung cancer risk are not decreased by taking high-dose supplements containing vitamins E or C or selenium. Vitamin and mineral supplements can be dangerous Proper balance and adequate levels of essential nutrients is important for a range of complex processes in our body. High doses of vitamin supplements are unsafe Many people mistakenly believe that since small amounts of vitamins are good for you, then large amounts must be better.

Taking higher than recommended doses of some vitamins may cause health problems. Such as: Vitamins A, D, E and K are fat soluble, which means they are stored in the body and if taken in high doses can be toxic. High doses of some water-soluble vitamins, such as vitamin B6, can also become toxic.

Large folate intakes can hide vitamin B12 deficiencies. High levels of vitamin B6 have also been linked to some types of nerve damage. Doses of vitamin C above one gram can cause diarrhoea. Excessive amounts of vitamin C in the body can also interfere with medical tests — such as diabetes tests, by giving a false result.

High doses of vitamin A may cause birth defects, as well as central nervous system, liver, bone and skin disorders. High-dose vitamin E supplements have been linked to higher rates of early death mortality. Large doses of minerals can also lead to health problems Excessive doses of some minerals may also cause problems for example: At just five times the RDI, zinc, iron, chromium and selenium can be raised to toxic levels in the body. Large intakes of fluoride especially in childhood may stain, and even weaken, the teeth.

Very large doses of fish oil can lead to decreased blood clotting. Iron toxicity is also common. Even a small amount over the RDI can cause gastrointestinal upset, nausea and black bowel actions poo. Severe toxicity can lead to coma and even death. Stay safe and keep to the recommended dose For a healthy adult, if supplements are used, they should generally be taken at levels close to the RDI.

Vitamin and mineral supplements are a short-term measure Taking vitamin and mineral supplements is a short-term measure. To some extent, you can think of these vitamins as time-release micronutrients. Your body squirrels away the excess and doles it out gradually to meet your needs. Together this vitamin quartet helps keep your eyes, skin, lungs, gastrointestinal tract, and nervous system in good repair.

Here are some of the other essential roles these vitamins play:. Because fat-soluble vitamins are stored in your body for long periods, toxic levels can build up. This is most likely to happen if you take supplements.

The body needs, and stores, fairly large amounts of the major minerals. Major minerals travel through the body in various ways. Potassium, for example, is quickly absorbed into the bloodstream, where it circulates freely and is excreted by the kidneys, much like a water-soluble vitamin.

Calcium is more like a fat-soluble vitamin because it requires a carrier for absorption and transport. One of the key tasks of major minerals is to maintain the proper balance of water in the body.

Sodium, chloride, and potassium take the lead in doing this. Three other major minerals—calcium, phosphorus, and magnesium—are important for healthy bones.

Sulfur helps stabilize protein structures, including some of those that make up hair, skin, and nails. Having too much of one major mineral can result in a deficiency of another.

These sorts of imbalances are usually caused by overloads from supplements, not food sources. Here are two examples:. A thimble could easily contain the distillation of all the trace minerals normally found in your body. Yet their contributions are just as essential as those of major minerals such as calcium and phosphorus, which each account for more than a pound of your body weight.

The other trace minerals perform equally vital jobs, such as helping to block damage to body cells and forming parts of key enzymes or enhancing their activity. Trace minerals interact with one another, sometimes in ways that can trigger imbalances. Too much of one can cause or contribute to a deficiency of another.

Here are some examples:. Antioxidant is a catchall term for any compound that can counteract unstable molecules such as free radicals that damage DNA, cell membranes, and other parts of cells. Your body cells naturally produce plenty of antioxidants to put on patrol. The foods you eat—and, perhaps, some of the supplements you take—are another source of antioxidant compounds.

Carotenoids such as lycopene in tomatoes and lutein in kale and flavonoids such as anthocyanins in blueberries, quercetin in apples and onions, and catechins in green tea are antioxidants.

The vitamins C and E and the mineral selenium also have antioxidant properties. Free radicals are a natural byproduct of energy metabolism and are also generated by ultraviolet rays, tobacco smoke, and air pollution. They lack a full complement of electrons, which makes them unstable, so they steal electrons from other molecules, damaging those molecules in the process.

Free radicals have a well-deserved reputation for causing cellular damage. But they can be helpful, too. When immune system cells muster to fight intruders, the oxygen they use spins off an army of free radicals that destroys viruses, bacteria, and damaged body cells in an oxidative burst. Vitamin C can then disarm the free radicals.

Antioxidants are able to neutralize marauders such as free radicals by giving up some of their own electrons. When a vitamin C or E molecule makes this sacrifice, it may allow a crucial protein, gene, or cell membrane to escape damage. This helps break a chain reaction that can affect many other cells.

Each of the nutrients that has antioxidant properties also has numerous other aspects and should be considered individually. The context is also important—in some settings, for example, vitamin C is an antioxidant, and in others it can be a pro-oxidant.

Articles and advertisements have touted antioxidants as a way to help slow aging, fend off heart disease, improve flagging vision, and curb cancer. And laboratory studies and many large-scale observational trials the type that query people about their eating habits and supplement use and then track their disease patterns have noted benefits from diets rich in certain antioxidants and, in some cases, from antioxidant supplements.

But results from randomized controlled trials in which people are assigned to take specific nutrients or a placebo have failed to back up many of these claims. On the opposite extreme of deficiency is toxicity, when the amount of a micronutrient goes far beyond what our bodies can process. For most vitamins and minerals there is a maximum value for intake, above which negative toxic effects can occur, particularly when consumed over a long period of time.

Even micronutrients that have a lower risk of toxicity such as water-soluble vitamins, can still cause harmful effects when taken in amounts that go above and beyond recommendations. Toxic levels of micronutrients are more easily reached through supplements than foods, particularly in the case of minerals and fat-soluble vitamins. Our diet should be our main source of micronutrients.

Vitamins and minerals are naturally present in a variety of nutrient-dense foods such as fruits, vegetables, nuts, pulses, whole grains, vegetable oils, fish, meat, and dairy. Since no single food contains the full spectrum of micronutrients, the key to a healthy diet is to ensure a good balance and variety of these foods on a regular basis.

However, there are other things we should keep in mind when aiming to improve our intakes of vitamins and minerals:. While some nutrients can be reduced, others can become better absorbed by the body.

In turn, cooking can make fat-soluble vitamins present in some vegetables — such as carotenoids vitamin A in carrots or vitamin K in spinach — become more available for absorption, particularly if small amounts of fat-rich foods, such as olive oil, are added. Storing our foods correctly is also important since some micronutrients - particularly vitamins — can lose their function if exposed to light and oxygen for long periods.

For example, if those foods are at the same time high in fat, sugar or salt, they might not be your best choice. In some cases, the diet alone is not sufficient to provide us with the recommended amounts of specific micronutrients and supplementation is advised to prevent us from getting insufficient levels or a deficiency. Before adding supplements to your diet, check with your health care professional or consult your national guidelines to assess your individual needs.

And remember, supplements will not compensate for an unhealthy diet! In this database , you will find all the information on the essential vitamins and minerals in our diet, including their roles in our bodies, the recommended amounts, in what foods we can find them, and what happens if we have too little or too much of them. You can then test your newly gained knowledge by doing this quiz!

Dive into the world of vitamins and minerals Last Updated : 11 January Every day, our bodies work around the clock orchestrating thousands of different tasks that keep us alive and functioning well. What is the difference between macro- and micronutrients? What are vitamins? What are minerals? Major or macro-minerals are needed in relatively large amounts, usually above mg, or even a few grams per day, to keep our health. Trace elements, sometimes also referred to as micro-minerals, are needed in much smaller amounts, usually below one milligram micrograms , or a few milligrams mg per day, to keep our health.

How much of each micronutrient do we need? So, what happens if we have too little or too much of a specific vitamin or mineral? What happens if we have too little a. Those include: Infancy and childhood Our early years are a period of rapid growth and development which are supported by specific amounts of vitamins and minerals. When diets rarely include animal products Vegans, vegetarians or those who rarely consume animal products such as meat, fish, eggs and dairy might need vitamin B12 supplementation as they have very few - or none — dietary sources of this vitamin, which is essential for the normal functioning of our brains and nervous system.

What happens if we have too much a. How to get enough micronutrients? However, there are other things we should keep in mind when aiming to improve our intakes of vitamins and minerals: 1. Supplement if needed, but with caution In some cases, the diet alone is not sufficient to provide us with the recommended amounts of specific micronutrients and supplementation is advised to prevent us from getting insufficient levels or a deficiency.

Explore the vitamins and minerals database! References Bender A. In: Rodwell, W. Harper's Illustrated Biochemistry. McGraw-Hill Education, pp Vitamin and mineral requirements in human nutrition. Geneva, Switzerland: WHO.