uses JavaScript to provide the best possible experience for our content, but your browser has it disabled. Learn how to enable it here.


Product Reviews (1)

Search term may appear only in full report available to members. Join now for full access.

Clinical Updates (6)

Search term may appear only in full report available to members. Join now for full access.


Concern Over Carnitine Causing Cardiovascular Disease

Intake of L-carnitine from supplements (and from red meat) may foster atherosclerosis (hardening of the arteries), according to new research. Once ingested, L-carnitine is converted in some people to a compound which reduces the normal clearing of cholesterol from arteries.

For more details, see the updated reviews of B Vitamin Supplements & Energy Drinks and Protein Powders, as some of these products contain L-carnitine. The Acetyl-L-Carnitine Supplements review has also been updated because acetyl-L-carnitine is chemically similar to L-carnitine, suggesting a potential concern.

Does Melatonin Increase Alzheimer’s Risk?

My doctor said that melatonin may increase the risk of Alzheimer's as some sleeping pills do. Is this true? See the answer in Concerns and Cautions section of the Melatonin Supplements Review.

Vitamin D and Allergy

Vitamin D is known to modulate the immune system. Having sufficient levels is associated with reduced risk of allergy and asthma. A recent study showed that giving vitamin D to pregnant women and their infants resulted in fewer infants being allergic to house dust mites and needing to see a doctor for asthma. For details, see "Allergy," as well as "Asthma," in the What It Does section of the Vitamin D Supplements Review >>

Hair & Nail Supplements Can Skew Lab Tests

There are reports of high-dose biotin (common in "hair and nail" supplements) causing false readings on blood tests. Be sure to tell your doctor if you're taking high-dose biotin. Get the details in the Biotin section of the B Vitamin Supplements Review.

Signs of Too Much Vitamin D

Doctors were surprised to discover that symptoms exhibited by a 64-year old woman were due to very high levels of vitamin D from supplements. Learn about the symptoms of too much vitamin D in the Concerns and Cautions section of the Vitamin D Supplements Review. Also see our Top Picks among vitamin D supplements and learn How Much Is Too Much vitamin D.