Vitamin D’s reputation shines more brightly than ever
as research links this nutritional superstar to
heart health, cancer protection and much more.
Researchers have known for years that
vitamin D helps strengthen bones—and that was the extent of their interest. But
the sunshine vitamin’s plain-Jane image is getting a glamorous makeover: New studies have revealed numerous D health benefits, from cardiovascular support to pain relief and much more. Scientists also now realize that many people simply aren’t getting as much of this vitamin as they need—and that supplementation plays a crucial role
in maintaining healthy D levels.
D Deficits Hurt the Heart
Vitamin D affects heart health in several ways. Inadequate levels have been linked to high blood pressure, a key risk factor. This is especially true for people who live where winters are cold, which cuts exposure to the sunlight that helps create D in the skin. Low vitamin D levels have also been linked to other cardio dangers, including stiff blood vessels and inflammation. Some good news: Early lab studies indicate that activated D supplements may help slow the progression of heart failure.
D on the Brain
Cells in the brain are studded with vitamin D receptors, particularly in areas linked with higher-level processing and memory functions, although scientists aren’t exactly sure how D affects these cells. It is known that people with low levels are more prone to Parkinson’s disease; a lack of the sunshine vitamin may also be associated with the dark moods of depression and premenstrual syndrome (PMS).
The D Way to Immune Balance
Vitamin D helps modulate the immune system. This keeps it from being either sluggish, leading to increased infection risk, or hyperactive, which can lead to autoimmune disorders in which the body attacks itself. Two such diseases, type 1 diabetes (the one that often starts in childhood) and multiple sclerosis, have been linked to inadequate D.
Dampening Pain with D
According to several studies, less vitamin D equals more chronic pain, with D-deficient women being the most susceptible, especially to back pain. (Pain is also a sign of weakened bones and D is crucial to bone health; see page 46.) In addition, low vitamin D is linked with muscle weakness. In one study, supplemental D and calcium increased muscle strength and decreased the risk of falling by nearly 50%.
Boning Up on D
Vitamin D deficiency is best known for causing rickets in children, a condition in which weak bones bow out under pressure. However, inadequate D is just as harmful for adults. A lack of D can help promote the development of osteoporosis, which leads to brittle bones that break easily; low levels of this vitamin have been linked to increased risk of hip fractures in women.
How Much D Do You Need?
What worries researchers is that up to 50% of the US population may be deficient in vitamin D. The government currently recommends that
people aged 50 to 70 get 400 IU a day and those
over 70 get 600; a number of studies support taking 1,000 IU a day or more. Your best bet is to undergo blood testing to learn what specific dosage would best suit your needs.
More D, Less Cancer?
Cells walk a multistep path on the way to malignancy. Vitamin D appears to interfere with several of those steps; it inhibits uncontrolled cell growth and prods cells into staying in place instead of spreading. In one study, colon cancer patients with high D levels saw their survival rates increase by 48%. Having healthy levels of vitamin D may provide breast cancer protection as well.