Can Any Supplements Slow Down Metabolism?

It's a nice idea, but there's no supplement out there that can rev up your metabolism and turn you into a calorie-burning machine. At the same time, though, nothing in the supplement aisle will grind it to a halt, either. But a few supplements have been connected to a less-than-optimal metabolism.

Especially if you're working toward a weight-loss goal, it's important to understand which types of supplements can interfere with — or benefit — your body's daily functions.

B vitamins promote the normal metabolism of carbohydrates, protein and fat, per the Cleveland Clinic. Missing out on these vitamins can make you feel sluggish.

Aside from taking a supplement (most multivitamins contain plenty of B vitamins), you can get B vitamins from seafood, fortified breakfast cereals and meat.

One of the body's control centers for metabolic activity is the thyroid. Low thyroid activity, known as hypothyroidism, can produce symptoms including weight gain, fatigue, muscle weakness, thinning hair and depression, per the Mayo Clinic.

Biotin, a supplement commonly taken to improve hair growth, doesn't affect the thyroid directly, but it can make hypothyroidism hard to diagnose. Biotin supplements can interfere with common tests used to assess thyroid function, according to the American Thyroid Association.

Biotin supplements can result in falsely high levels of thyroid hormone, which can potentially cause thyroid tests to read at normal levels when hormone levels are suboptimal. To ensure your results and diagnosis aren't being compromised, it's important to discuss biotin supplementation with your physician if he or she is conducting thyroid tests.

This well-known vitamin is revered for being an antioxidant powerhouse, but vitamin C also plays an important role in fat metabolism. In fact, an August 2006 study in ​Nutrition & Metabolism​ notes vitamin C is required for the biosynthesis of carnitine, a molecule required for the breakdown of fatty acids in the body.

Researchers found those with marginal vitamin C levels broke down 25 percent less fat per kilogram of body weight during a treadmill test compared to those who had adequate vitamin C levels.

Additional research, published in a January 2019 edition of ​Redox Biology​, found that people diagnosed with metabolic syndrome require a higher intake of vitamin C. The additional vitamin C helps to break a cycle of antioxidant depletion that could be contributing to higher weights and chronic conditions, the authors concluded.

While taking vitamin D doesn't slow your metabolism, not getting enough might. A July 2012 study in ​The American Journal of Clinical Nutrition​ showed that people who were overweight and obese and took a vitamin D supplement lost more weight than participants who did not take a supplement.

Taking a vitamin D supplement and/or consuming foods rich in vitamin D — like eggs, yogurt and salmon — may help keep your metabolism from lagging.

Magnesium is responsible for more than 300 enzyme reactions in the body that contribute to metabolic function. If you're lacking in magnesium, your metabolism may suffer.

May 2014 research in the ​Archives of Medical Research​ found oral magnesium supplements improved metabolism and lowered blood pressure.