Caution With Ashwagandha

Ashwagandha may decrease the effectiveness of immunosuppressant drugs and, according to a recent case report, may trigger transplant rejection. Get the details in the Concerns and Cautions section of the Ashwagandha Supplements Review. The section includes information about other potential side effects of ashwagandha.

Coffee and Heart Disease

Research published this week suggests a link between a moderate coffee consumption and reduced risk of cardiovascular disease and death. Get the details in our article about Coffee and Heart Health.

Vitamin D and COVID-19

Many preliminary studies have linked adequate vitamin D levels with reduced risk of COVID-19 or less severe disease. However, a recent study did not find a benefit among people who had been supplementing with amounts generally above the recommended daily intake requirement for vitamin D. See the details in the COVID-19 section of our Vitamin D Supplements Review. Also, see our Top Picks for vitamin D.

Magnesium, Niacin and Blood Pressure


Two studies this week showed the risk of high blood pressure to be lowest among people with adequate, but not excessive, dietary intakes of magnesium and niacin.

Also, see which foods are good sources of magnesium and, separately, good sources of niacin.

Vitamin D & Risk of COVID Death

A recent study in the U.S. found that people hospitalized with COVID had much lower rates of death with certain blood levels of vitamin D. Get the details in the COVID-19 section of our Vitamin D Supplements Review. Also, see our Top Picks for vitamin D.

High-Dose Vitamin C for COVID-19?

Does high-dose vitamin C help in people with severe COVID-19? See what a new study showed in the COVID-19 section of our Vitamin C Supplements Review.

Nicotinamide Riboside to Slow Aging and Reverse NAD+ Decline?

Nicotinamide riboside, a form of niacin, has been promoted to slow aging, partially based on the belief that it raises NAD+ levels that fall with age. A new study raises doubts about this. Get the details in the Niacin section of our B Vitamin Supplement Review. Also, learn about a concern with taking too much nicotinamide riboside.