Find out which types of portable air cleaners are best for wildfire smoke. Also see our top picks among air cleaners (including for use in reducing viral exposure).

The CDC has shortened its recommended time for isolation after confirmed infection as well as quarantine after exposure. Get the details, plus find out if people should be retested before ending isolation.

Find out how much sun exposure was needed in a recent study to significantly increase vitamin D levels in older people in the Getting Vitamin D from Sunlight section of our Vitamin D Supplements Review. Also see our Top Picks among vitamin D supplements.

Can vitamin D supplementation improve outcomes in people with melanoma skin cancer? See what a new study found in the What It Does section of the Vitamin D Supplements Review.

Also see our answer to the question: Do any supplements or foods help prevent sunburn or skin damage from sun exposure? Can any increase your risk of sun-related skin damage?

Does exposure to midday sun increase already sufficient vitamin D blood levels? Get the surprising answer from a new study in the Getting vitamin D from sunlight section of the Vitamin D Supplements Review. Also see our Top Picks among vitamin D supplements.

Can using a CPAP humidifier increase one's exposure to potentially dangerous PFAS? Find out in our updated answer about Avoiding PFAS.

Earlier research has suggested an association between higher vitamin D levels in the blood and reduced risk of heart attack. But blood levels are affected by both sun exposure as well as intake of vitamin D. A new study shows that men with higher vitamin D intakes from foods and supplements have a 14% reduction in their risk of cardiovascular disease and stroke. However, the study found no reduction among women. The amount of vitamin D intake shown to be beneficial and possible reasons why a benefit was not found in women are provided in the updated "What It Does" section of our Product Review of Vitamin D Supplements. More >>