Betaine -- also called betaine anhydrous, or trimethylglycine (TMG) -- is a substance that's made in the body. It's involved in liver function, cellular reproduction, and helping make carnitine. It also helps the body metabolize an amino acid called homocysteine. The US Food and Drug Administration (FDA) approved betaine to treat a genetic condition where too much homocysteine builds up in the body.

Scientists have also proposed betaine as a way to lower homocysteine levels in people who don't have the genetic disease. This is because higher levels of homocysteine are associated with heart disease and stroke. But researchers don't yet know exactly how high levels of homocysteine and heart disease are related. It's unclear as to whether homocysteine itself is harmful, or whether it is just an indicator of increased risk for heart disease.

Heart Disease

Studies suggest that betaine, along with vitamins B6, B12, and folic acid, helps reduce higher levels of homocysteine. Some studies show that high levels of homocysteine may encourage atherosclerosis (hardening of the arteries).

Betaine supplements may increase cholesterol levels, which could work against any treatment for heart disease. If you are at risk for heart disease, your doctor may test levels of homocysteine in your blood. Ask your doctor whether taking supplements of betaine, folic acid, and other B vitamins makes sense for you.

Homocystinuria

Some people have a genetic condition called homocystinuria, in which homocysteine levels build up in the body. They are at much higher risk of developing heart disease and osteoporosis as early as their 20s. Betaine supplements are used to lower levels of homocysteine in people with this inherited health condition.

Liver Disease

Studies in rats suggest that betaine may help protect against harmful fatty deposits in the liver. These deposits can be caused by alcohol abuse, obesity, diabetes, and other causes. Preliminary studies in people have shown similar results. More research is needed.

Dry Mouth

One study found that a toothpaste containing betaine helped relieve dry mouth.

Cancer

One study found that higher betaine intake protects against lung cancer by minimizing the adverse effects of smoking. A second suggests that betaine intake may lower the risk of breast cancer.

Food sources of betaine include:

• Beets
• Broccoli
• Grains
• Shellfish
• Spinach

Betaine supplements are manufactured as a byproduct of sugar beet processing. They are available in powder, tablet, and capsule forms.

Pediatric

Betaine is not recommended for children unless prescribed by your child's doctor to treat homocystinuria, a genetic condition.

Adult

Recommended doses of betaine vary depending on the condition being treated. Ask your doctor to help you determine the right dose for you.

Betaine is usually taken with folic acid, vitamin B6, and vitamin B12.

Because of the potential for side effects and interactions with medications, you should take dietary supplements only under the supervision of a knowledgeable health care provider.

Most side effects from betaine are mild and include diarrhea, stomach upset, and nausea.

Betaine can raise total cholesterol levels. People who are overweight, have heart disease, or are at risk for heart disease, should not take betaine without talking to their provider.

People with kidney disease should not take betaine.

In people with kidney disease, betaine may interfere with drugs taken to lower cholesterol levels in the blood.

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