The True Source Of Vitamin D
There are many reasons not to like the shorter days that come this time of year,
ranging from the psychological to the practical. Here's one people might not be
thinking much about. Less sunlight (not to mention less time in the sun when it
is out) means less vitamin D, which is transferred to people's bodies directly
from the sun's rays. And that can carry some health risks. "In the winter, you
don't have much choice," said Dr. Kenneth Aquilino, an internist at Holyoke
Medical Center. "There's less sunlight during the day, and it's cold outside,
especially in the New England area. So a lot of people are at risk of
developing vitamin D deficiency."
Dr. Aquilino says “ Ingesting foods rich in vitamin D won't do much good unless the vitamin is
triggered by exposure to the sun - which many kids aren't getting enough of.”
Vitamin D, which maintains normal levels of calcium and phosphorous, aids in the
absorption of calcium, which directly affects bone health. Not getting enough,
he explained, can cause rickets in children and malfused bones and bone loss in
adults. "With osteomalacia, the bone starts eating itself away, and in older
adults there's osteoporosis," said Aquilino. "So there are some major problems
and diseases associated with vitamin D deficiency."
"We live in the northern latitudes, and anywhere above Georgia, people tend to
be at risk for vitamin D deficiency," said Aquilino, due to colder temperatures
during the winter months keeping people indoors. But the issue is also one of
lifestyle, he reiterated, given that today's children, even in the warmer
seasons, don't spend as much time in outdoor play as kids did, say, 20 or 30
years ago. "Today, they're more likely to play video games, and they do that
indoors," he said. "For whatever reason, they're not out playing, and so they
are at risk for vitamin D deficiency." And forget trying to have it both ways,
like moving the computer next to a window. "The thing is, the sun exposure has
to be outside," said Aquilino. "Indoors, essentially getting sun through the
glass, is not going to cut it." In other words, it's time to power down, get
outside, and power up.
For many children, however, lack of adequate sunshine has become a year-round
problem because they don't spend as much time outdoors as young people from
previous generations did. Several factors, including parents' safety concerns
about playing outside, the growing popularity of video games and the Internet,
and increasing rates of childhood obesity due to sedentary lifestyles, have
converged to keep children out of the sun, meaning they're not getting that
natural dose of vitamin D.
Even adults have increasingly drifted away from an outdoorsy lifestyle, and away
from the sun - a problem that's only exacerbated when the weather gets colder.
"In New England, because of our climate, the consensus is that very few people
are getting enough sun exposure," said Paula Serafino-Cross, a registered
bariatric dietitian at Baystate Medical Center. "In the hospital, we see lots
of patients with low vitamin D levels, and people who are homebound or nursing
home-bound are especially at risk," she added. "We're testing everybody now, at
all ages, and we're finding a prevalence of vitamin D deficiency. If we lived
closer to the equator, spending more time outdoors, walking to work, it would
The term 'vitamin D' actually refers to several different forms of the nutrient.
Two are important to people: ergocalciferol (vitamin D2), which is synthesized
by plants, and cholecalciferol (vitamin D3), which is synthesized by humans in
the skin when exposed to ultraviolet rays from the sun. Foods may be fortified
with either vitamin D2 or D3.
Vitamin D is present in a number of foods and drinks, said Aquilino, among them
milk, cereals, yogurt, egg yolks, orange juice, and some seafood, including
tuna and salmon. "The problem," he continued, "is that we still need exposure
to the sun, because that's what activates the vitamin D and starts the process
to convert it to an active form. Even if you eat plenty of vitamin D in your
diet, if you don't have sun exposure, it won't do much good. Think of the sun
as the trigger that starts the whole process. Without that switch, you can't
process the vitamin D."
The liver and kidneys are both active in this process, he added, and people with
problems with those organs are also at higher risk for deficiency. Others at
risk include people with malabsorption syndromes (like cystic fibrosis) or
inflammatory bowel disease (such as Crohn's disease).
Vitamin D deficiency can exacerbate such medical issues, said Serafino-Cross,
noting that gastric-bypass surgery poses a risk of malabsorption, yet many
patients begin the surgery in that condition. "So surgeons are actually
treating patients prior to surgery and monitoring their vitamin D levels after
surgery," she said. In older patients, she added, an adequate intake of vitamin
D might stem the incidence of hip and other bone fractures, which often trigger
a permanent downward spiral in health.
For those who don't exactly worship the sun, it takes only about 10 minutes of
direct sunlight exposure per day, on average, to prevent the diseases caused by
inadequate vitamin D. The fact that deficiency remains a problem speaks volumes
about modern lifestyles, especially among children, whose bones are still
growing and who especially need plenty of vitamin D.
from the Massachusetts business journal-BusinessWestonline “Shady Dealings Lack of Sunshine Has Many People at Risk of Vitamin D Deficiency” by Joseph Bednar