Do fat-soluble vitamin supplements do more harm than good?

Everyone is looking for that magic pill that will make you healthy, but supplements aren’t always the answer. “The benefits often outweigh the disadvantages,” says Joan Manson, chief of preventive medicine at Brigham and Women’s Hospital in Boston, USA.

However, store shelves are full of nutritional supplements. Are they all meaningless? No, for some people, extra vitamins can give an extra boost. But you may need fewer vitamin pills than you think. Experts are especially cautious with fat-soluble vitamins. Why? What is the difference between fat-soluble vitamins and water-soluble vitamins?

Water-soluble vitamins versus fat-soluble vitamins

Water-soluble vitamins, such as vitamins C and B, dissolve quickly and are processed by the body. They are not saved. “You’re urinating excess amounts of water-soluble vitamins,” says Alice Lichtenstein, MD, director of the cardiovascular nutrition team at the USDA Jean Mayer Center for Human Nutrition Research on Aging at Tufts University.

This works differently with fat-soluble vitamins. These vitamins are stored in the liver and in the body’s fatty tissue. This can be useful. For example, your body stores vitamin D in the summer to compensate for your lack of exposure to sunlight in the winter months. But it also means that fat-soluble vitamins can build up to unhealthy levels in the body.

There are four fat-soluble vitamins, but care must be taken especially with vitamins A and E.

Too much vitamin A: why is it harmful?

Vitamin A is important for normal growth, your immune system and your eyes. This vitamin is commonly found in animal products, but also in sweet potatoes, spinach and carrots. If you get enough vitamin A through your diet, it is considered safe and healthy.

But taking too much vitamin A is not good for your body. The Nutrition Center states that eight hundred micrograms of vitamin A for men and 680 grams for women is considered a healthy amount. The safe upper limit is three thousand micrograms per day.

Because large amounts of vitamin A increase the risk of birth defects in the eyes, heart, and other organs, pregnant women are advised not to take vitamin A supplements. It is also best to avoid liver products during pregnancy.

Vitamin A supplements can also cause side effects for women who are not pregnant. “In the long term, high doses of vitamin A can cause liver disease, high cholesterol, bone and muscle pain, and visual problems,” says Kate Zeratsky, a registered dietitian at the Mayo Clinic in Rochester, USA. “Early symptoms of too much vitamin A include dry skin, nausea, headache, fatigue, and hair loss.”

Controversy surrounding vitamin E

Then there is fat-soluble vitamin E, which is perhaps more controversial. When this vitamin is found naturally in food, for example in fish, avocados and nuts, it is a powerful antioxidant. But experts are not yet convinced that vitamin E supplements are healthy. Why do they doubt? There are different forms of vitamin E and not every variant has been equally researched.

“There are eight chemical forms of vitamin E, but most supplements contain synthetic alpha-tocopherol,” says Yufang Lin, MD, MD, at Cleveland Clinic’s Center for Integrative Medicine. This type of vitamin E appears to carry more risks. “This may be an argument for choosing foods rich in vitamin E rather than supplements.”

Eat a handful of nuts instead of vitamin tablets

So, next time you’re at the supermarket, it’s better to put a bowl of nuts or avocado in your basket instead of vitamin pills. “It’s a common misconception that vitamin supplements are good for everyone,” says registered dietitian Jane Messer. “They may be healthy for some people in certain circumstances, but supplements are not necessary for everyone. Additionally, they can be expensive and are not always taken without risks.”