vitamin D

You may
think vitamin D is little more than a component in your daily multivitamin.

But the
so-called “sunshine vitamin” is more complicated — and potentially more
beneficial — than you might have imagined.

It’s long
been known that vitamin D helps bone growth and strength by increasing the
body’s absorption of calcium, magnesium, iron, and other beneficial minerals.

Absorbing sunlight
and eating fatty fish are two simple ways to boost vitamin D levels.

But some of
vitamin D’s unique characteristics — and its lesser-known benefits — may make
it worth talking to your doctor about.

A unique
vitamin

Unlike other
members of the vitamin alphabet, vitamin D defies easy classification.

That’s
because it could actually be considered a hormone, since it’s synthesized in
the liver and kidneys.

Another
unique aspect of vitamin D is the fact that, apart from fatty fish oil, vitamin
D is rarely found in food.

The
essential nutrient is dependent on body chemistry — and because everybody is
different — it’s worth getting an expert opinion.

“I always
measure vitamin D,” Dr. Jenny Goodman, Nutritional and Environmental Medicine
specialist from the British Society for Ecological Medicine (BSEM), told
Healthline. “It’s very important because you can theoretically overdose — it’s
very unlikely, but still technically a risk. You could never overdose on
vitamin C or the B vitamins, because they’re water-soluble and you just pee out
whatever you don’t need.”

Any B or C
vitamins will be gone from your system within a few hours, Goodman noted. But,
that’s not the case with vitamin D.

That’s why
she tends to measure patients’ levels before suggesting they take it.

Goodman said
that humans once got enough sunlight to produce sufficient vitamin D, but times
have changed.

“We all
evolved from Africa, we didn’t evolve with clothes on, and we didn’t evolve
indoors. So our basic natural state is to be running around under an African
sun with very little covering on,” she explained.

“Even in the
Northern Hemisphere, until the Industrial Revolution, most people worked
outside all the time, and they got by.”

After the
industrial revolution, people began spending more time indoors, in offices, and
at home.

Goodman said
that unless you happen to have a job as a gardener or a landscape designer, you
likely won’t get enough sun, even through the summer, because you’re just not
outdoors enough.

“People’s
requirements vary, which is why levels should be measured,” she added.

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Old
benefits, new benefits

The link
between healthy vitamin D levels and healthy bones is well-known.

But more
recent research sheds light on a wider range of possible benefits.

Researchers
at the Harvard School of Public Health (HSPH) found that low levels of vitamin D could accelerate the progression of multiple sclerosis (MS) for people
in the early stages of the disease.

Getting
enough vitamin D may protect against this.

Recent research out of the University of Birmingham,
published in PLOS ONE, suggests that increased levels of vitamin D in the blood
can help optimize muscle strength.

Lead study
author, and Clinical Lecturer at the Institute of Metabolism and Systems
Research at the University of Birmingham, Zaki Hassan-Smith, PhD, told
Healthline in an email that researchers hope to learn more about this
connection in future studies.

“We found
that the receptor which vitamin D is known to act through was present in muscle
from our research volunteers,” he wrote.

“We also
observed associations between serum vitamin D levels and a number of genes that
are involved in muscle function,” he added.

Hassan-Smith
says that his team is seeking funding for trials of vitamin D in different
groups, including the elderly and high-performance athletes, in order to better
understand optimum doses of vitamin D. He also points to other research into
possible health benefits.

“A recent BMJ study has suggested that there may be
benefit in [vitamin D] reducing respiratory tract infections, but the jury is
still out,” he wrote. “There are large scale randomized controlled trials due
to report in a number of health outcomes that should give us a clearer idea in
the next two to three years.”

Goodman says
that this BMJ study, which shows a link between vitamin D levels and immune
system health, could be a game-changer.

“Our bodies
are producing cancer cells all the time, but what happens is our immune system
detects that there’s an alien cell and it destroys it, just as it would destroy
a bacterium — and it does not work properly without vitamin D,” she said. “I
see particularly low levels of vitamin D in my patients with breast cancer.”

She suggests
that anyone who has had cancer, particularly breast cancer, should have their
levels checked immediately.

Goodman also
suggests a link between healthy vitamin D levels and brain function, telling
Healthline, “You’ve got to remember that the brain is a fatty organ … All the
nerve cells are basically coated in a myelin sheath, which is basically fat.”

She
emphasized that people need their fat-soluble vitamins, particularly vitamin D.

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Get it
checked

Multivitamin
supplements may promise a well-rounded nutritional regimen, but they often
don’t deliver, said Goodman.

“I
definitely do not recommend multivitamins,” she said. “Firstly, they tend to
have tiny amounts of everything, and secondly, they tend to have lots of
fillers and rubbish in them.”

Some options
may have too much vitamin A, and many use a cheap, synthetic form of vitamin D,
called vitamin D-2, according to Goodman.

“Vitamin D-3
is the real thing. It’s what our body makes from sunshine. Multivitamins really
are a cheap substitute for eating properly,” she added.

It’s worth
noting that the body cannot create vitamin D if it doesn’t have the necessary
components to do so. “One of the causes of vitamin D deficiency, especially in
women, is low-fat diets,” said Goodman.

People who
don’t have enough fat in their diets won’t get enough vitamin D because it’s a
fat-soluble vitamin, she explained

Goodman
closed with this advice for keeping your vitamin D levels up during the winter
months: “Eat oily fish — that is, salmon, trout, mackerel, sardines, and so on —
through the winter, make sure you’re getting as much sunshine exposure as you
can, and if you’re poorly, get your vitamin D levels tested.”

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