What Happens to Your Body When You Take Vitamin D Supplements Every Day Long Term?

Ouadie Rhabbouron
Hands dispensing gel capsules from a bottle evident focus on supplements or vitamins
Sunshine is the body’s primary source of vitamin D.SCIENCE PHOTO LIBRARY / Getty Images

  • Taking vitamin D daily can support bone strength, muscle function, and balance.
  • Benefits are most noticeable in people who don’t get enough vitamin D from food or sunlight.
  • Too much vitamin D can cause problems, so experts recommend testing levels and consulting a healthcare provider.

Vitamin D is one of the most commonly used supplements, popular among people with a deficiency or those who think they might have one. But what happens when you take vitamin D pills daily for a while? Here are three potential benefits—and one risk—to keep in mind.

1. Stronger Bones

If you’re not getting enough vitamin D through food or sun exposure, a daily vitamin D supplement may benefit your bones.

When you ingest vitamin D, your kidneys jump into action and transform it into calcitriol, the biologically active form of the vitamin.1 According to Stanford Medicine endocrinologist and internal medicine physician Marilyn Tan, MD, FACE, FACP, calcitriol then promotes calcium absorption from the intestines, which ultimately helps bones grow. Vitamin D also supports phosphorus absorption, which leads to bone mineral growth, she added.2

If you aren’t deficient in vitamin D, however, taking extra vitamin D is unlikely to have a meaningful effect on bone health. A 2022 study found that healthy people who took vitamin D had no fewer fractures than those taking a placebo.3

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