Can Too Many Supplements Harm You?


Nutritional supplements can be beneficial, but they are not magic pills.

While it may be good to take a multivitamin if you don’t eat the right foods or get enough of certain nutrients, some people take too many supplements without realizing they are overloading their system.

Supplements, just like medications, can be beneficial when they are used correctly and as directed. However, if you rely too heavily on supplements and don’t give your body the natural resources it needs for optimal function, you could actually do yourself more harm than good.

It’s always best to get your nutrients from food whenever possible. Eating a variety of healthy foods, especially fruits and vegetables, will give you all the nutrients you need and help to keep your body functioning optimally.

Water-Soluble Vitamins

Some vitamins dissolve in water, so your body doesn’t have a way of storing them. They will just be excreted from your system if you take too much without being absorbed.

The water-soluble vitamins are vitamin C and the B-complex vitamins:

  • B1 (thiamine)
  • B2 (riboflavin)
  • B3 (niacin)
  • B5 (pantothenic acid)
  • B6 (pyridoxine)
  • B7 (biotin)
  • B9 (folate)
  • B12 (cobalamin)

Many of these have been demonstrated to be safe even in high doses.

But high doses of Vitamin C can cause gastrointestinal problems and migraines.

Vitamin B3 (niacin) can increase blood pressure and cause liver damage.

Vitamin B6 (pyridoxine), when overconsumed over a long period of time, can cause severe neurological symptoms and other risks.

Vitamin B9 (folate) might negatively impact mental and immune functions when taken in high dosages.

Fat-Soluble Vitamins

Fat-soluble vitamins are stored in the body’s tissues. This means they are not so easily flushed out of the system and can accumulate to dangerous levels.

Vitamin K has been shown to have a very low potential for toxicity, but it may affect certain medications such as antibiotics and warfarin.

The other fat-soluble vitamins, A, D, and E, should probably not be taken in high dosages. High-dose supplements of vitamins A, D, and E (and the water-soluble vitamin C) do not appear to be effective for preventing or treating disease and can be very harmful to your health.

Are Vitamin Supplements Safe?

While taking a multivitamin and supplements can be helpful, it’s important not to overdo it. Try to eat a healthy diet that gives you all the nutrients you need, and only take supplements when necessary. Supplements should not be used as a substitute for healthful eating. 

If you consider taking higher doses of any vitamin supplement, discuss it with your doctor first. High-dose supplements can cause serious side effects and may interact poorly with some medications.