Your guide to knowing which supplements to consider and ones to avoid

How popular are supplements? A 2016 survey found nearly 70 percent of Americans take one, and 78 percent are confident the supplement provides what's stated on the label.

Yet, many pills have been shown to provide no results at all.

Magnesium keeps your heart steady and immune system strong, but while magnesium supplements are sometimes marketed as a fix for everything from low energy to trouble sleeping, that may not be the case.

A Harvard Medical School article states there's no evidence to support those claims, and whenever possible, it's best to get your magnesium from leafy greens and beans.

Another supplement you may not need to take is calcium. It might be doing more harm than good.

"There's this paradox where dietary calcium from food sources, seems to be associated with reduced risk, a lower risk of kidney stones, but calcium from supplements actually increases the risk of kidney stones," said Dr. Erin Michos of Johns Hopkins University School of Medicine

Researchers at Harvard also found that ginkgo biloba and echinacea showed no benefit in clinical studies.

So what should you take?

Probiotics have produced positive results in the treatment and prevention of digestive disorders and urinary tract infections.

And, vitamins B and D do improve your brain, bones, heart and muscle development.

As for fish oil, experts say you are best off eating more fish and getting your omega-3s through food.