Vitamin D is crucial for muscle strength and bone health.
It also helps the body maintain bone density, which reduces the risk of fracture, osteoarthritis and osteoporosis. Research also indicates vitamin D helps the immune system fight the flu and infections, and reduces the risk of many common diseases, including cancer, cardiovascular disease, depression and diabetes.
The recommended daily intake of vitamin D seems to be up for debate within the medical community, and the recommended methods for getting that daily dose of vitamin D are full of confusion as well. Here, we dive into the details of vitamin D, exploring its role in the body, how much we may need and the best ways to go about getting it.
One of the main reasons to aim for adequate vitamin D levels is because this vitamin is essential to building and maintaining strong bones. For massage therapists, whose success rests on being able to perform on their feet day after day, this is not a minor concern.
“Being a massage therapist is a very physically demanding job,” said Laura Lacey, a New Jersey-based massage therapist who holds a degree in nutritional counseling. “It puts a lot of strain on the body, especially the joints and bones.
“Having good body mechanics helps, of course, but even with that, if the massage therapist has low levels of vitamin D, she could suffer from joint pain, [and] her bones could become porous and brittle, which would lead to an increased risk of broken bones and fractures,” Lacey continued.
When it comes to having strong bones, vitamin D is vital, and many years of scientific research have proven the importance of this vitamin for the prevention of serious bone problems, such as rickets and osteoporosis.
“Without sufficient vitamin D, bones can become thin and brittle,” said Harry F. Hester, D.C., president and CEO of Dee Cee Laboratories, a company that manufactures dietary supplements. “Vitamin D sufficiency prevents rickets in children and osteomalacia in adults. Together with calcium, vitamin D also helps protect older adults from osteoporosis.”
In addition to the connection between vitamin D and bone health, scientists are finding links between vitamin D and a host of other health issues, spanning the spectrum from mood to metabolism. This new insight is changing our understanding of vitamin D and how much we may need it for optimal health.
“Research has found that vitamin D is used by almost all of the body processes,” Lacey said. “It is needed for calcium metabolism, maintains normal blood levels of calcium and phosphorous, [and] it provides cardio function and blood pressure control.
“Vitamin D is also used by the immune system and helps with the prevention of cancers such as breast cancer, prostate cancer and colon cancer,” she continued. “With type 1 diabetes, it helps inhibit insulin secretion from the pancreas.”
According to the Vitamin D Council, a nonprofit organization that aims to keep up with the latest research on vitamin D and make recommendations based on this research, vitamin D plays a key role in the gene expression that dictates development, growth and maintenance of the body.
“Vitamin D’s metabolic product (calcitrol) is actually a secosteroid hormone that is the key that unlocks binding sites on the human genome,” states a report by the Vitamin D Council. “The human genome contains more than 2,700 binding sites for calcitrol, [and] those binding sites are near genes involved in virtually every known major disease of humans.
“Acting through the vitamin D receptors (VDR), calcitrol controls the expression of genes,” the report continues, “activating about two-thirds of the ones it controls, suppressing the rest.”
Vitamin D Dosage
As research continues to pour in on the potential benefits of vitamin D and how it plays into our overall wellness, the hard science on how much we may need and how it might benefit our health is still not clearly known.
In 2010, amid the confusion about vitamin D, the U.S. and Canada asked the Institute of Medicine (IOM) to weigh in on the issue. The health branch of the National Academy of Sciences, the IOM reviewed more than 1,000 published studies and heard testimony from scientists and stakeholders on the topic of vitamin D.
The review confirmed vitamin D and calcium are crucial for bone health, and the IOM’s comprehensive report was used to update the 1997 dietary reference intake for both vitamin D and calcium. According to the IOM, most adults need no more than 600 international units (IU) of vitamin D per day to maintain bone health, along with 700 to 1,300 milligrams of calcium. A fact sheet on the website of the National Institutes of Health also indicates 600 IU, with different recommended amounts for children under 1 year of age and adults older than 71.
The IOM review was unable to find the consistent results necessary for reaching conclusions about the role vitamin D plays in other health issues, such as protection against cancer, heart disease, autoimmune diseases and diabetes. According to the report, studies on vitamin D as it relates to these other health issues “point to possibilities that warrant further investigation.”
“Past cases, such as hormone replacement therapy and high doses of beta carotene, remind us that some therapies that seemed to show promise for treating and preventing health problems ultimately did not work out and even caused harm,” said Catharine Ross, chair of the IOM Food and Nutrition Board committee that was assigned to review the dietary reference intake for vitamin D. “This is why it is appropriate to approach emerging evidence about an intervention cautiously, but with an open mind.”
Other experts, however, suggest the government recommendation of 600 IU of vitamin D per day for most adults may be too low. For example, Lacey and Hester recommend 2,000 IU of vitamin D per day, and the Vitamin D Council advocates at least 5,000 IU of vitamin D each day.
“Recent studies have shown that [600 IU of vitamin D per day] may be too low—government levels usually indicate the very smallest amount needed,” Lacey said. “Because of environmental factors and the new evidence about the role vitamin D plays in various body processes, not just bone health, a larger amount of vitamin D is needed.”
According to the IOM, the upper intake level of vitamin D per day among most adults is 4,000 IU. This represents the amount of vitamin D the IOM reports is safe for daily consumption.
The Sunshine Vitamin
For millions of years, humans have derived their daily intake of vitamin D from the sun’s rays—ultraviolet B (UVB) rays, to be specific. When the right amount of skin is exposed to the right amount of sun for the right amount of time, this triggers the natural production of vitamin D within the skin.
However, several issues can make this method of deriving vitamin D confusing and problematic. For starters, the medical community has made it clear that at least 40 percent of your skin, especially your torso, should be exposed for the optimal production of vitamin D.
If you choose this approach for getting your daily dose of vitamin D, be sure to look into your exact latitude, altitude, skin type and other factors that may influence just how much time you should spend in the sun, and use caution to prevent skin cancer.
For those who would rather avoid the potential health issues associated with sun exposure, as well as people who live in regions where natural vitamin D production is not possible during winter, other options are needed in order to obtain a healthy dose of vitamin D.
To begin with, some foods contain vitamin D. Among the best of these is the flesh of fatty fish, such as salmon, tuna and mackerel. Smaller amounts of vitamin D are also found in beef liver, cheese, egg yolks and some mushrooms.
Some foods have been fortified with vitamin D, such as milk, which usually has around 100 IU per cup, along with various brands of orange juice, yogurt, cereal and other products.
Given the limited number of foods that contain vitamin D, experts suggest some combination of sunshine, food and supplements may be necessary to get an adequate amount of vitamin D each day.
“People should not rely on food sources alone for the body’s need for vitamin D,” Hester said. “Since the diet does not always provide enough vitamin D and the sun can damage the skin, it’s best to take a vitamin D supplement.”
However you get your vitamin D, doing so could benefit your health on myriad levels. As Lacey noted, “Our bodies are our tools, and we need to keep them in optimum condition.”
Brandi Schlossberg is an avid bodywork client and full-time journalist based in Reno, Nevada. She has written many articles for MASSAGE Magazine, including “These Credentials Can Help Grow Your Practice” and “Bring Benefits of Sea Kelp to Clients.”