During wintertime, I suggest you take one simple step to boost your immune system, lift your mood, and reduce your risk of disease: Make sure your blood level of vitamin D is in the optimal range.
You may not realize what a toll the dark days of winter levy on our health. Cold and flu season arrives. Depression rates soar. Aches and pains, as well as autoimmune disorders, tend to flare up. Fracture incidence increases. Heart attack and death rates climb. And vitamin D levels plummet.
The reason vitamin D deficiencies run rampant during the winter is because the primary source of this very important vitamin is ultraviolet radiation from sunlight, which stimulates the synthesis of vitamin D in the skin. But, in wintertime, the angle of the sun plus absorption by the atmosphere prevents penetration of the UV rays that produce vitamin D.
Thousands of studies have shown that vitamin D is protective against a long list of diverse health conditions, ranging from heart disease and cancer to autoimmune disorders and osteoporosis. For example, a study published in the Journal of Biological Chemistry found a link between low levels of vitamin D in people with diabetes and increased risk of clogged arteries.
The good news is that you can easily and safely elevate your blood level of vitamin D into the protective range of 50–80 ng/mL: Simply take 2,000–5,000 IU of supplemental vitamin D3 per day. I recommend that you take this amount for three months, have your vitamin D blood level tested, and increase or reduce your dose to keep your level in the target range.
Just imagine the impact: dramatic reductions in pain and suffering, better health and more graceful aging, and greater longevity—not to mention the savings in health care expenditures.