Winter Depleting Vitamin D Levels In The Northeast
From Science Daily Winter Weather Depriving City Dwellers Of Vitamin D (2/15)
Residents of snowy, northern U.S. cities are at risk of vitamin D deficiency and
worse, may not even know it.
During Buffalo's winter months, nearly 50 percent of people have insufficient
amounts of vitamin D and 25 percent may
be considered deficient, says nutrition researcher Peter Horvath of the
University at Buffalo School of Public Health and
Health Professions. Those most at risk: the elderly, pregnant and nursing women,
and people of color, whose skin acts as a natural sunscreen.
Unlike other vitamins, vitamin D is created by the body when the skin absorbs
ultraviolet sunlight. But during winter
months, people wear more clothes, are less likely to spend time outside and
direct sunlight is hard to come by due to the
Earth's tilt away from the sun. Maintaining proper levels is crucial due to the
vitamin's widespread effect on the body.
"Every cell in the body is responsive to vitamin D," says Horvath, associate
professor in the Department of Exercise and
Nutrition Sciences. "If you're deficient, you won't see the health effects for
years and it could take months to get your
levels back up."
Deficient levels of vitamin D may result in:
• Lower bone density.
• Weakened immune system.
• Increased risk for type 2 diabetes.
• Higher susceptibility to some cancers.
• Increased risk of death from cardiovascular disease.
• Cognitive impairment in older adults.
The elderly, whose skin produces lower amounts of the vitamin, often suffer
difficulty with functional fitness, such as
opening cans or standing up, when vitamin D levels are low.
Insufficiency is of particular concern in pregnant women and nursing mothers
because it affects children at a time when
their bones are developing and can result in rickets - the softening of bones,
For those exposed to northern winters, he recommends vitamin D supplementation
of between 1,000 and 2,000
international units a day. Foods that are a rich source of the vitamin are
wild-raised salmon and oily fish, breakfast
cereals, enriched milk and cod liver oil.
Another source is irradiated mushrooms, a current focus of Horvath's research.
The mushrooms "basically go through a
little tanning bed" and produce a huge amount of the vitamin, he says. In his studies, Horvath has found that these mushrooms also aid glucose
regulation, improving weight loss, especially among women.
By keeping vitamin D levels high in the summer, he says people should be in good
shape for the colder months.