Vitamin D Benefits You Should Know—and How to Get More in Your Diet
Vitamin D is famous for its
bone-building and strengthening powers. “vitamin D promotes absorption of
calcium in your gut, which ultimately allows for normal mineralization of your
bones,”a nutritionist and author tells Health. Basically, the calcium that benefits your bones wouldn't
be able to do its job without vitamin D. “You need vitamin D for bone
growth—and to prevent bones from becoming brittle.” When teamed with calcium,
it can help prevent osteoporosis, a disease that signifies that the density and
quality of bone are reduced, she adds.
Vitamin
D can help strengthen muscles
Along with its bone-building
abilities, vitamin D is also influential in strengthening muscles. “Lack of
vitamin D in the body can increase the risk of having weak muscles, which in
turn increases the risk of falls,” Lana Nasrallah, MPH, RD, clinical dietician
at UNC Health, tells Health. This is especially important for the
elderly. “Vitamin D may help increase muscle strength thus preventing falls,
which is a common problem that leads to substantial disability and death in
older adults.”
Vitamin
D can support the immune system and fight inflammation
Dr. Nasrallah adds that vitamin D
can also help build immunity. “It can support the immune system by fighting off
harmful bacteria and viruses,” she says. In fact, this role in possibly
preventing infections has become a critical concern during COVID-19 pandemic,
as researchers are interested in its potential role in infection outcomes.
“There is particular interest in its role in viral infections such as influenza
and coronavirus,”a Yale Medicine hematologist, oncologist, and nutritionist,
tells Health. He points to a 2017 BMJ analysis of 25 randomized control trials comparing vitamin D
supplements to placebos, which found that vitamin D reduced the risk of acute
respiratory infection with either daily or weekly vitamin D supplementation,
particularly in individuals who were deficient in it. “Studies indicate that
high latitudes and winter season are risk factors for both low vitamin D,
increased influenza, and other respiratory illness and adverse outcomes,” he
says. “We now are seeing a similar pattern with higher mortality rates in
COVID-19 infections," though more research still needs to be done to
determine whether the link is causal or merely a correlation.
Vitamin
D can help strengthen oral health
Because vitamin D helps our body
absorb calcium, it plays a crucial role in supporting oral health, lowering the
risk of tooth decay and gum disease. A 2011 review notes that while the research is
scant, there's an "emerging hypothesis" that the vitamin is
beneficial for oral health, due to its effect on bone metabolism and "its
ability to function as an anti-inflammatory agent and stimulate the production
of anti-microbial peptides."
Vitamin D can help prevent Type 1
and Type 2 diabetes
While studies are not conclusive,
vitamin D may be helpful for preventing both type 1 and type 2 diabetes, says
Newgent. One such study,
found that while vitamin D on its own did not effectively lower the risk of an
overabundance of sugar in the blood, a combined daily intake of >1,200 mg
calcium and >800 IU vitamin D could effectively lower the risk of type 2
diabetes.
Vitamin
D can help treat hypertension
According to a 2019 review suggests that vitamin D may play a
role in treatment of high blood pressure—one of the markers of cardiovascular
disease—says Newgent. According to authors of the review, “even short-term
vitamin D deficiency may directly raise BP [blood pressure] and promote target
organ damage.” The researchers went on to add that, "due to the high
correlation between vitamin D and hypertension, vitamin D supplementation
therapy may be a new insight in the treatment of hypertension."
Vitamin
D can help you lose weight
Dr. Boyd points out that obesity is
a known risk factor for low vitamin D levels—which means more vitamin D may
help with weight loss. One 2009 study found that, in overweight or obese women
with low calcium levels, those who took a daily dose of calcium paired with
vitamin D were more successful shedding pounds than those who took a placebo
supplement, due to an “appetite-suppressing effect” of the combination.
Vitamin
D can help battle depression
The sun can brighten up your mood,
and so can vitamin D. According to a 2017 review article, the
researchers found "a significant relationship between depression and
vitamin D deficiency.” While they acknowledged that more research is needed to
define the exact workings of it—such as, if low vitamin D levels are a cause or
effect of depression—the authors recommend “screening for and treating vitamin
D deficiency in subjects with depression” noting that it is an “easy,
cost-effective and may improve depression outcome.”
Vitamin
D may help reduce the risk of certain cancers.
Dr. Boyd points to various
studies—that provide some evidence that
vitamin D may have cancer fighting powers. “Evidence is increasing that vitamin
D supplementation may improve cancer outcomes,” he explains. The cancers for
which the most human data are available are colorectal, breast, prostate, and
pancreatic cancer.
The NCI specifically calls out a few
reasons why researchers are interested in a link between vitamin D and a
lowered risk of cancer. The organization points out that some research shows
that incidence and death rates for certain cancers were lower among individuals
living in southern latitudes, where levels of sunlight exposure are relatively
high, than among those living at northern latitudes, though additional research
needs to be done to find a specific causal or correlational link between more
sunlight exposure and a lower risk of cancer. More experimental evidence, per
the NCI, shows, that cancer cells and of tumors in mice, vitamin D
has been found to have several activities that might slow or prevent the
development of cancer cells and tumors in mice, including promoting cellular
differentiation, decreasing cancer cell growth, stimulating cell death
(apoptosis), and reducing tumor blood vessel formation
(angiogenesis).
How
to get more vitamin D
Despite being readily available
through sunlight, some foods, and supplementation, many Americans are still
getting inadequate amounts of vitamin D—according to the most recent
information from the Centers for Disease Control and Prevention, two-thirds of
the population had sufficient vitamin D, defined by the Institute of Medicine
as a serum 25-hydroxyvitamin D (25OHD) value of 50–125 nmol/L. Because you
can't necessarily find out if you a vitamin D deficiency on your own, the best
thing to do is to consult a medial expert, says Cynthia Sass, RD, MPH,
contributing nutrition editor for Health. "Ideally the best
approach is to have your blood vitamin D level tested to find out if your blood
vitamin D level is within the adequate range,” she explains. “This determines
if a supplement is needed in order to achieve adequate blood vitamin D status,
and if so, the proper dosage of supplemental vitamin D.”
If you find out you are deficient or
lacking in vitamin D intake, there are a few key ways you can up your daily
dosage—staring with getting around 20 minutes of sunlight several times a week,
according to Newgent. "The major cause of vitamin D deficiency is
inadequate exposure to sunlight, an increasing feature in modern life,"
says Dr. Boyd. But remember: You still need to wear sunscreen whenever you step
outside—even to get vitamin D.
Aside from the sun, you can also get
extra vitamin D through a few (albeit very few) foods, like fatty fish
(including salmon, tuna, mackerel, and sardines) and mushrooms (some of which
are exposed to ultraviolet (UV) light to increase vitamin D levels), says Drs.
Nasrallah and Newgent. Foods like milk, orange juice, yogurt, and breakfast
cereals can also be fortified with vitamin D. And of course, you can always go
the supplement route, in the form of vitamin D3, if your doctor thinks it's
necessary. According to Dr. Boyd, many doctors now consider a daily dose
of 1000-2000 IU of D3 safe and will assure optimal levels for most adults. As
for when to take it, because vitamin is fat soluble, he suggests pairing it
with your largest meal of the day, “containing fat to assure maximal
absorption.” But again, check in with your doctor before you decide to try vitamin
D in supplement form.
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