How can vitamins be bad for you

Please consult a medical professional before adopting any of the suggestions on this page. You must never disregard professional medical advice or delay seeking medical treatment based upon any content of this newsletter. Here are a few vitamins that are proven to be toxic if taken in excess, as well as their symptoms of overdose: Iron- Nausea, bloody stools, diarrhea, dizziness, headache, fluid build-up in the lungs and fever.

Vitamin A-Hair loss, liver damage, severe headaches, bone pain, blurred vision, dry skin and vomiting Vitamin D- Abnormal heart rhythm, constipation, frequent urination, muscle weakness and confusion.

For women of childbearing age, taking prenatal vitamins with folic acid is recommended by the American College of Obstetricians and Gynecologists to help prevent birth defects. Multivitamins might also be prescribed by your doctor if you have malabsorption syndrome, a condition in which the body does not properly absorb vitamins and minerals. Rich in omega-3 fatty acids, fish oil has been touted as a means to reduce heart disease. However, more and more evidence shows that fish oil supplements have questionable heart benefits.

A study published January 3, , in The New England Journal of Medicine NEJM found that omega-3 fatty acid supplements did nothing to reduce heart attacks, strokes , or deaths from heart disease in middle-aged and older men and women without any known risk factors for cardiovascular disease.

An earlier study, published in May in NEJM , looked at people at high risk for cardiovascular disease and also reported no benefit. The best way to get adequate amounts is by eating a variety of foods that are rich in them, including:. Kava is an herb that in concentrated forms has been used to treat general anxiety disorder with some success. An Australian study published online in in the journal Trials found that the South Pacific plant can be an effective alternative treatment to prescription medication for people diagnosed with generalized anxiety disorder GAD.

An earlier, smaller study, published in October in the Journal of Clinical Psychopharmacology , also showed that taking kava significantly reduced anxiety compared with a placebo in people with GAD. However, taking too much kava, or taking it for too long, has been linked to serious liver damage , including hepatitis , cirrhosis , and liver failure. As a result, according to the NIH , the FDA has warned that people, especially those with liver disease or liver problems, or those who are taking drugs that can affect the liver, should talk to their healthcare practitioner before using kava.

In addition, the National Center for Complementary and Integrative Health reports that heavy consumption of kava has been associated with heart problems and eye irritation. Tofu, tempeh, and soy milk are all good sources of protein , fiber, and a number of minerals.

Some women also take soy in supplement form because the plant contains estrogen-like compounds called isoflavones that may help relieve symptoms of menopause. However, concerns have been raised that the isoflavones in soy supplements may contribute to an increased risk of breast cancer.

The good news is that large-scale studies have not shown any increased breast cancer risk from eating whole soy foods, such as tofu and edamame , according to the Dana Farber Cancer Institute in Boston. In fact, at least one study, published March 6, , in the journal Cancer , which looked at 6, breast cancer survivors, linked eating the equivalent of one serving of soybeans a week to a 21 percent lower risk of death from all causes during the nearly year follow-up period.

But not enough research has been done on soy protein isolate SPI — the powder formed by removing the protein from the rest of the plant — to know its effect on breast cancer risk, Millstine says. In addition to supplements, SPI is often found in power bars, veggie burgers, and some soups, sauces, smoothies, and breakfast cereals. By subscribing you agree to the Terms of Use and Privacy Policy. Health Topics. Health Tools. For instance, people on long-term restrictive weight loss diets or people with malabsorption problems, such as diarrhoea, coeliac disease, cystic fibrosis or pancreatitis, can benefit from supplements.

Folic acid supplements are strongly recommended for women planning a pregnancy to reduce the risk having a baby with neural tube defects, like spina bifida. Also, people who follow vegan diets, especially if pregnant, may benefit from vitamin B12 supplements.

If you need to take a supplement, it is best to take multivitamins at the recommended dietary level, rather than single nutrient supplements or high-dose multivitamins. Many people think that vitamin C helps prevent the common cold. Despite exhaustive research across the world, there is still no strong evidence to prove this.

Some studies have shown that taking large doses of vitamin C more than 1, mg per day continuously or when you first develop cold symptoms, may ease some of the symptoms and the duration — on average, making it about half a day shorter. It does not prevent you catching a cold. You also need to consider the health risks associated with taking large doses of vitamin C. Large doses may cause nausea, abdominal cramps, headaches, fatigue, kidney stones and diarrhoea.

Excessive amounts of vitamin C in the body can also interfere with medical tests, such as diabetes tests, giving a false result. Some vitamin and omega-3 fatty acid deficiencies can lead to emotional disturbances. However, if you are feeling run down, it is more likely to be due to stress, depression or unhealthy lifestyle habits such as insufficient sleep or smoking , rather than a vitamin deficiency. Vitamin E is widely promoted as a beneficial antioxidant that can help prevent heart disease.

Unfortunately, several large-scale reviews have conclusively found no evidence that vitamin E supplements prevent death from heart disease. In fact, there may be greater risk of all-cause death from taking such supplements. Vitamin A in large doses does not cure cancer and can be toxic, particularly if taken as pills rather than food. There is some evidence that vitamin E could play a small role in preventing some cancers although, equally, there is evidence that it could speed up the onset of other types of cancer.

However, this has not been proved or disproved. While it is argued by some that megadoses of antioxidants can help with the effectiveness of conventional cancer treatments, such as chemotherapy and radiotherapy, the evidence is far from supporting this.

In fact, it has been shown that megadoses of antioxidants can actually interfere with some medical treatments for cancer by helping to protect the cancer cells that the therapies aim to destroy.

Vitamin E is often singled out as the potential fountain of youth. However, there is no evidence that taking large doses of any vitamin can either stall or reverse the effects of ageing.

Neither can any one vitamin restore a flagging sex drive or cure infertility. In developed countries like Australia, vitamin deficiency is rare, but the inadequate intake of some vitamins, as a result of an unhealthy diet, is not so rare and has been linked to a number of chronic diseases. These include cardiovascular disease, cancer and osteoporosis.

There is ongoing research to study the effects of taking vitamin supplements to prevent chronic disease, and evidence around nutrition and diet is constantly changing. It is important that you consult with your doctor before taking vitamin supplements in high doses. This page has been produced in consultation with and approved by:. The size of a standard drink can vary according to the type of alcohol.

The Alexander technique stresses that movement should be economical and needs only the minimum amount of energy and effort. A common misconception is that anorexia nervosa only affects young women, but it affects males and females of all ages. Antioxidants scavenge free radicals from the body's cells, and prevent or reduce the damage caused by oxidation.