If you expect sunshine to provide you with vitamin D, then make sure your shadow is shorter than your height. The long shadow we see in November is proof the sun is not doing it for us any more, and it's time to take care of ourselves.

Reinhold Vieth, PhD#

We are in the middle of the golden age of vitamin D research. New discoveries on the health benefits of solar ultraviolet-B (UVB) light and vitamin D are being announced at a rapid pace.

William B Grant, PhD#

Be aware that adequate vitamin D is required for the immune system to fight infections!

Adrian Gombart, PhD#

Vitamin D supplements lower risk of acute respiratory infections among children with vitamin D deficiency.

Carlos A Camargo, MD, DrPH#

We know that low vitamin D status is associated with a higher risk of undesirable outcomes during critical illness. Indeed, optimal 25(OH)D levels appear to promote distinct biological advantages, especially when considering immune function during times of stress.

Sadeq A Quraishi, MD#

Vitamin D deficiency is a global pandemic that has serious health consequences for children and adults. Improvement in the world’s vitamin D status could significantly reduce risk of many chronic illnesses including cardiovascular disease, autoimmune diseases, type 2 diabetes and many deadly cancers as well as infectious diseases including upper respiratory tract infections, influenza and tuberculosis.

Michael F Holick, PhD, MD#

It’s now quite clear that our ancestral vitamin D status was a lot higher than most citizens of the industrialized nations achieve today. A prudent person, knowing that, would strive to elevate his or her 25(OH)D level into that range by taking the amount of vitamin D needed to get back to ancestral status. The burden of proof should be placed on anyone who says we can get by on less.

Robert P Heaney, MD#

Something so simple -- vitamin D supplementation -- could improve the health status of millions and so becomes an elegant solution to many of our health problems today.

Carol L Wagner, MD#

Virtually everyone that works indoors is at risk for insufficiency and more than likely deficient. The problem is even worse in the fall and winter.

John J Cannell, MD#

Because vitamin D is so cheap and so clearly reduces all-cause mortality, I can say this with great certainty: vitamin D represents the single most cost-effective medical intervention in the United States.

Gregory A Plotnikoff, MD#