The following water-soluble vitamins have set ULs, as they can cause adverse side effects when taken in high doses:

But routinely getting an overload of vitamins and minerals can hurt you. Too much vitamin C or zinc could cause nausea, diarrhea, and stomach cramps. Too much selenium could lead to hair loss, gastrointestinal upset, fatigue, and mild nerve damage.

“Most people think it’s fine to take as much as they want,” says Rosenbloom. “I know people who take 10,000 mg a day.” However, the upper tolerable limit is 2,000 mg a day. “People at risk for kidney stones can increase that risk; people also can get diarrhea.

• Vitamin C.
• Vitamin B3 (niacin).
• Vitamin B6 (pyridoxine).
• Vitamin B9 (folate).

You can—but it’s probably not a good idea. For some supplements, optimal absorption can depend on the time of day taken. Not only that—taking certain vitamins, minerals, or other supplements together can also reduce absorption and may result in adverse interactions, which can be harmful to your health.

Large doses of minerals can compete with each other to be absorbed. Don’t use calcium, zinc, or magnesium supplements at the same time. Also, these three minerals are easier on your tummy when you take them with food, so if your doctor recommends them, have them at different meals or snacks.

When to take supplements He suggests taking your dietary supplements at night isn’t advisable. “Digestion slows down during sleep, so taking your nutrient supplement late at night would not be associated with an efficient absorption.”

Never take more than the recommended dose of a multivitamin. Avoid taking more than one multivitamin product at the same time unless your doctor tells you to. Taking similar vitamin products together can result in a vitamin overdose or serious side effects.

Vitamin D is so important to our overall health. It even makes it possible to absorb calcium and promote healthy bone growth and oral health. As an added benefit, it’ll help you feel happier and healthier overall to improve your quality of life.

Getting enough vitamin D can keep your hormone levels in check and may help enhance weight loss and decrease body fat. In turn, losing weight can increase vitamin D levels and help you maximize its other benefits, such as maintaining strong bones and protecting against illness ( 29 , 30 ).

The benefits of the sunshine vitamin are no secret. Besides boosting mood and promoting calcium absorption, recent studies have shown that vitamin D may also aid in weight loss. For people with extra belly fat, a vitamin D supplement may be beneficial.

Vitamin D stimulates hair follicles to grow, and so when the body does not have enough, the hair may be affected.