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D-mannose is a simple sugar found in many fruits. It is related to glucose. It also occurs naturally in some cells in the human body.

Other names for D-mannose are:

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  • Carubinose
  • D-manosa
  • Mannose
  • Seminose

Why do people take D-mannose?

D-mannose is used to treat a rare disease called carbohydrate-deficient glycoprotein syndrome type 1b.

This disease is passed down through families. It makes you lose protein through the intestines. Some reports say D-mannose slows down this protein loss and makes your liver work better. It may also reduce bleeding disorders and low blood sugar in people with this disease.

D-mannose may also treat or prevent urinary tract infections (UTIs). Animal research suggests the supplementstops certain bacteria from sticking to the bladder walls.

Scientists think that the bacteria stick to the sugar instead. This helps the bacteria leave the body through your urine. Fewer bacteria in the bladder lowers your risk of a UTI. However, no studies of D-mannose have been done in people to determine if it effectively treats or prevent UTIs.

Some studies suggest D-mannose may play a useful role as a "prebiotic." Prebiotics are substances that may help your body by stimulating the growth of "good" bacteria in your digestive system.

In some lab studies and studies in mice, D-mannose components were shown to increase the growth of "good" bacteria. This suggests D-mannose may have some use for people with dysbiosis, an imbalance in good and bad bacteria.

D-mannose supplements are taken by mouth.

Can you get D-mannose naturally from foods?

D-mannose is found naturally in high amounts in many fruits. Such fruits include:

  • Apples
  • Oranges
  • Peaches
  • Some berries such as blueberries and cranberries

What are the risks of taking D-mannose?

Long-term studies in mice suggest it is safe when taken by mouth in appropriate amounts.

You should be cautious about using D-mannose if you are pregnant or breastfeeding, because there has not been enough study on its safety in these circumstances.

Side effects of D-mannose may include:

D-mannose supplements should be used with caution if you have diabetes. It may make it harder to control your blood sugar.

High doses of D-mannose may cause kidney damage.

Always tell your doctor about any supplements you are taking, including natural ones and those bought without a prescription. That way, your doctor can check on any potential side effects or interactions with any medications.

Supplements are not regulated by the FDA.

WebMD Medical Reference

Reviewed by David Kiefer, MD on June 14, 2015

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