Like many of you, my patients and I are enjoying these warm, sunny days, but we all know the cooler temperatures, and the grey cloudy skies of winter are inevitable. Sunday, Nov. 7 is when we will change the clocks for daylight savings time, and there are steps we can take now to maintain or improve our health.

I am interested to learn that a daily dose of vitamin D may just be what people in northern climates need to get through the long winter, according to researchers at Loyola University Chicago Marcella Niehoff School of Nursing (MNSON). This nutrient lifts mood during cold weather months when days are short and more time is spent indoors. My wife, Patty, is a registered dietician in our practice, and she hears positive feedback from our patients who increase their vitamin D intake during the winter months through vitamin supplements. Increasing consumption of foods naturally high in vitamin D such as wild salmon, wild catfish, sardines and codliver oil is not recommended due to potential toxicity levels. 

Vitamin D deficiency was virtually unheard of until about a decade ago, when people became more educated about the dangers of sun overexposure.

“Vitamin D deficiency continues to be a problem despite the nutrient’s widely reported health benefits,” said Sue Penckofer, PhD, RN, professor, MNSON, who coordinated the research study. “Chicago winters compound this issue when more people spend time away from sunlight, which is a natural source of vitamin D.” 

A “normal” diet is definitely not sufficient enough alone to manage appropriate vitamin D levels. A combination of adequate dietary intake of vitamin D, exposure to sunlight, and treatment with vitamin D2 or D3 supplements can decrease the risk of certain health concerns. The preferred range in the body is 30 — 60 ng/mL of 25(OH) vitamin D. 

Loyola faculty members plan to take vitamin D research a step further by evaluating whether weekly vitamin D supplements improve blood sugar control and mood in women with diabetes. Many of the 23 million Americans with diabetes have low vitamin D levels. Vitamin D deficiency results in part from poor nutrition, which is one fo the most challenging issues for people with diabetes. Depression is associated with increased insulin resistance, so people with diabetes have a greater risk for the disease than those without depression. Women also tend to have greater rates of depression and poorer blood sugar control than men with diabetes. 

“There is evidence to suggest that vitamin D supplementation may decrease insulin resistance,” Dr. Penckofer tells me. “If we can stabilize insulin levels, we may be able to simply and cost effectively improve blood sugar control and reduce symptoms of depression for these women.” Vitamin D deficiency also may be associated with hyperglycemia, insulin resistance, hypertension and heart disease.  In fact, Dr. Penckofer recently published another study in Circulation that reported on the role of chronic vitamin D deficiency in heart disease. 

Loyola is currently enrolling women in this clinical trial. In order to enter the study, they must be 18 to 70 years of age, have stable type 2 diabetes, signs of depression and no other major medical illness. Eighty women with type 2 diabetes and signs of depression will be given a weekly dose of vitamin D (50,000 IU) for a period of six months. Study participants will be evaluated at three points during this time.

“Vitamin D has widespread benefits for our health and certain chronic diseases in particular,” Dr. Penckofer said. “Our research may shed greater light on the role this nutrient plays in managing two conditions that impact millions of Americans. If proven to be successful, vitamin D may an important addition to care for diabetes and depression.”

Vitamin D also plays an important role in multiple sclerosis, cancer and heart disease.

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