BY KATHLEEN BARNES
Ever since skin cancer scares penetrated the national psyche in the mid-1980s, Americans have been conditioned to cover up and slather on sunscreen when we leave the house. Now experts say we haven’t been doing ourselves a favor, even when strictly using all-natural formulas. We’ve been blocking the sun’s life-giving rays, essential for the body’s production of vitamin D, and possibly prompting a host of health problems.
Safe Exposure Update
“Ninety percent of the vitamin D we get comes from the sun, and exposing arms and legs for a few minutes a day is enough for most people with no risk of skin cancer,” says Registered Nurse Sue Penckofer, Ph.D., a professor in the School of Nursing at Chicago’s Loyola University. She’s the lead researcher for the Sunshine 2 Study, a clinical trial investigating the vitamin’s vital role in relieving depression.
“Every tissue and cell of your body requires vitamin D to function properly,” says Michael Holick, Ph.D., a medical doctor who has pioneered vitamin D research at the Boston University Medical Center. A 40-year professor at the Boston University School of Medicine, he’s a fervent advocate of sensible sun exposure.
“Vitamin D is actually a hormone, essential for bone and muscle health. It plays a significant role in reducing the risk of infectious diseases, including cardiovascular problems and certain cancers, contributes to brain function and memory, and elevates mood, all while reducing early mortality,” explains Holick, author of The Vitamin D Solution: A 3-Step Strategy to Cure Our Most Common Health Problem. Yet, he says, about half of all Americans are among the 1 billion people worldwide that are vitamin D deficient.
Published vitamin D research in the U.S. National Library of Medicine turns up 74,486 studies and citations dating back to 1922, with nearly half done in the past 10 years; 478 of the total were authored or co-authored by Holick or cited his research. His work confirms that sensible sun exposure and supplementing with natural vitamin D3 brings vitamin D levels to the optimal 40 to 60 nanograms per milliliter (ng/ml). New research from the University of Surrey, in the UK, found D3 twice as effective in raising vitamin D levels as D2, which is often synthetically produced.
At least 10 hours a week outdoors in sunshine is crucial for children under 6 for development of healthy eyes. Otherwise, the risk of myopia increases, which in turn lends risk for cataracts and glaucoma in adulthood.
~University of Sydney Adolescent and Eye Study of 2,000 children
While the human body manufactures vitamin D as a response to sun exposure, eating certain foods like fatty fish, egg yolks and cheese can help. Fortifying foods with the vitamin is controversial. “It’s interesting that the right sun exposure will correct D deficiency rapidly, but won’t create an excess. Our bodies stop producing the hormone vitamin D once we have enough,” says Dr. Robert Thompson, an obstetrician, gynecologist and nutrition specialist in Anchorage, Alaska, and author of The Calcium Lie II: What Your Doctor Still Doesn’t Know.
Holick, who differentiates between unhealthy tanning and healthy sun exposure, recommends exposing arms and legs to noonday sun for five to 10 minutes three times a week for most people. He adds, “Everyone needs 1,500 to 2,000 international units of vitamin D3 [supplements] a day year-round, and obese people need two to three times that much, because their ability to manufacture vitamin D is impaired.”
Penckofer’s research confirms that fair-skinned people absorb the sun’s rays easily and quickly, while darker-skinned people have a natural sunblock, so they need much longer sun exposure to absorb the UVB rays that trigger the production of vitamin D. She remarks that inadequate vitamin D is a possible explanation for the greater risk of high blood pressure observed in African-Americans.
Holick contends that anyone living north of Atlanta, Georgia, cannot get enough winter sun exposure to maintain optimal vitamin D levels. “While vitamin D can be stored in the body for up to two months, a winter-induced deficiency is a convincing explanation for the seasonal affective disorder that strikes many in northern states in January, just two months after the weather turns too cold to get sufficient sun exposure,” explains Penckofer.
“In Alaska, we eat lots of fatty fish and take D supplements in winter. We know there’s no chance we’re getting the D we need from the sun, even when we’re sunbathing in negative 30 degrees Fahrenheit temperatures,” quips Thompson.
Kathleen Barnes is the author of numerous books on natural health, including Food Is Medicine: 101 Prescriptions from the Garden. Connect at KathleenBarnes.com.