Are vitamins helpful or harmful?

Vitamins are among the micronutrients that are important for life. Vitamin deficiency is not expected in a person who normally eats a balanced diet, and it is unnecessary to use ready-made vitamin products from the outside. In case of deficiency, it is necessary to take it with foods or as ready-made products, although it is not deficient, but using it as ready-made products may be harmful for some vitamins. Unfortunately, this topic is abused a lot. It is necessary to make a decision by examining the evidence on this issue, where there is a lot of false information.

If vitamin drugs, which have a toxic effect on the liver when stored in the body, are used without consulting a doctor, it may cause harm instead of benefit. Taking too much of one vitamin reduces the absorption of another. This causes health problems. Water-soluble vitamins are excreted in the urine, but fat-soluble vitamins and minerals are stored in the body. Excess intake of vitamins has a toxic effect on the liver. If the person using it is pregnant, this negative effect is also reflected on the baby and congenital abnormalities are seen in the baby. It is also undesirable to take vitamin drugs with food. Vitamin pills should be taken two hours before or after a meal. Otherwise, these drugs reduce the absorption of naturally taken vitamins. The Medical Letter on

An article on vitamin supplementation was published in Drugs and Therapeutics on July 18, 2005. In this article, the subject has been examined in the light of the evidence.

Vitamin E

The editors of “The Medical Letter” state that most of the vitamin E found in food is gamma-tocopherol, and this form acts as an anti-oxidant.

However, the vitamin E used in vitamin supplements is usually alpha-tocopherol, and this form may inhibit the anti-oxidant effect of gamma-tocopherol. Some experiments have even shown that alpha-tocopherol may have pro-oxidant effects.

High doses of vitamin E may affect the metabolism of vitamin K, which has an important role in blood coagulation, and platelet functions. A meta-analysis published in the Annals of Internal Medicine on January 4, 2005 concluded that use of more than 400 IU of vitamin E per day may increase the risk of death.

Randomized controlled studies are considered the “gold standard” in studies to show cause and effect. In a study conducted in this way, more than 9000 patients with vascular disease and diabetes were evaluated.

According to this study published in the Journal of the American Medical Association on March 16, 2005, it was observed that taking 400 IU of vitamin E daily did not prevent cancer or vascular diseases, but increased the risk of heart failure.

Another randomized study in 40,000 women aged 45 and older, published in the Journal of the American Medical Association on July 6, 2005, found that taking 600 IU of vitamin E daily did not provide benefits in preventing cardiovascular disease or cancer.

Therefore, vitamin E should not be used except for vitamin E deficiency, which is very rare, and should only be used with expert advice.

Vitamin A and Beta-carotene

Carotene, a source of vitamin A and vitamin A, is an anti-oxidant. But lab research suggests they may also have pro-oxidant effects.

A study in the Journal of the American Medical Association dated January 2, 2002 found that high intake of vitamin A with food, along with vitamin supplements, increased the risk of hip fracture in post-menopausal women.

An article published in the New England Journal of Medicine, dated August 10, 1995, found that one in every 57 babies born to women who took more than 10,000 IU of vitamin A daily was malformed.

According to an article in the April 14, 1994 issue of the same journal, the risk of lung cancer increases by 18% among Finns who take 20 mg of supplemental beta-carotene per day.

A large clinical trial in smokers and workers exposed to asbestos was stopped after no benefit was observed. In this study, it was found that a daily intake of 30mg beta-carotene and 25,000 IU of vitamin A may cause an increase in the incidence of lung cancer, cardiovascular death, and mean death. The results of the study were published in the New England Journal of Medicine on May 2, 1996 and the Journal of the National Cancer Institute on November 6, 1996.

Vitamin D

The editors of “The Medical Letter” state that the elderly, especially those with dark skin, have access to less vitamin D due to insufficient exposure to sunlight, decreased production of vitamin D in the skin, and decreased absorption and activation of the vitamin. Vitamin D, which will reduce bone loss, is 400 IU for men and women aged 51-70, and 600 IU for men and women over 70. Serious vitamin D deficiency is also seen in fair-skinned people who do not drink milk and do not go out into the daylight enough (such as closed ladies).

In a meta-analysis of randomized controlled trials published in the Journal of the American Medical Association on May 11, 2005, it was revealed that daily intake of 700-800 IU of vitamin D in people over 60 years of age reduced the risk of hip and other clinical fractures, but this effect was not observed in the use of 400 IU of vitamin D.

However, in another randomized controlled study published in the British Medical Journal on April 30, 2005, conflicting results were found. There was no evidence that the daily use of a combination of 800 IU of vitamin D and 1000 mg of calcium in 3000 women at high risk of fractures reduces the risk of clinical fractures.

C vitamin,

Daily intake of vitamin C is 300-400 mg. 250 ml of orange juice contains approximately 100 mg of vitamin C. A meta-analysis of three studies in elderly people published in the British Medical Journal on August 28, 1999 found no evidence that vitamin C caused a reduction in mortality.

Again, in the analysis published in the highly respected and non-profit “Cochrane Collaboration” in 2004, it was stated that vitamin C has no effect on the prevention of upper respiratory diseases such as colds.

The editors of The Medical Letter state that when high-dose vitamin C (> 1000mg) is taken, vitamin C cannot be adequately absorbed, so diarrhea may develop, and this risk may increase in people who are prone to developing kidney stones.

Vitamin B12

Atrophic gastritis occurs in 10-30% of elderly people. This problem causes impaired absorption of vitamin B-12, which is dependent on food. In this case, vitamin B12 to be taken with supplements can be absorbed from the stomach. For this reason, it is recommended that the elderly take more B12-containing foods, such as cereals, or take B12 supplements containing at least 2.4 mg of RDA.

Folate and Folinic Acid

With normal nutrition, 50 – 500 mg of folate is taken daily. But the absorption of folate depends on the content of the diet. Folic acid in vitamin supplements is absorbed at a rate of about 2 times more than in foods. Cereals absorb folic acid 215 -240 mg daily. increases.

However, the amount taken may not be sufficient to prevent neural tube defect, which is an important congenital anomaly. This anomaly can develop early when women do not know they are pregnant yet.

The daily intake of 400 mg of folic acid (which is found in many multivitamin supplements) by women of childbearing age significantly reduces the incidence of neural tube defects.

Low intake of folate causes homocysteine, an amino acid, to reach high levels in the blood. High homocysteine ​​is associated with increased risk of coronary heart disease, stroke, and peripheral vascular disease. Folic acid supplementation may lower homocysteine ​​levels, but it is not yet known whether this reduces coronary risk.

High doses of folic acid may mask vitamin B-12 deficiency. Therefore, it can lead to the progression of neurological disease.

Vitamin B6 (Pyridoxine)

In an article published in the American Medical Association dated February 4, 1998, it was observed that the incidence of coronary heart disease decreased in women who were found to take B6 and folate (more than 1.3 mg and 400 mg, respectively) by surveys. Randomized controlled trials have not yet been conducted, and the optimal dose and efficacy of vitamin B6 supplementation have not been established.

If we summarize the subject, we can draw the following conclusions;

Supplementation is necessary to ensure adequate intake of folic acid in young women and vitamins D and B-12 in the elderly.

There is no evidence that taking a vitamin C supplement prevents any disease or symptom.

-Women should not use vitamin A during pregnancy and after menopause. Also, no one should take high doses of beta-carotene.

-Vitamin E does not please your skin, it pleases those who sell it, does not make you younger, on the contrary, it makes you die faster.

A balanced diet rich in fruits and vegetables is safer than taking vitamin supplements.

We should not forget that no biological active substance can be without risk when used for a long time.

*Daily doses are recommended by the World Health Organization for healthy individuals.