If you’re looking to build strong bones, mitigate disease risk, and slow cognitive decline, then vitamin D is your new best friend.
According to Bryant’s School of Health and Behavioral Sciences Director Kirsten Hokeness, Ph.D., vitamin D plays many critical roles within the body to keep you healthy. This nourishing and noteworthy nutrient helps the intestine absorb calcium from food so the body can build strong bones and maintain bone density as you age; it’s also been linked to maintaining a healthy immune system, assisting the body’s natural production of antimicrobials, and playing a role in the development and activity of innate cells and immune cells.
“People with low levels of vitamin D have shown to be at increased risk for infections, particularly respiratory infections, which is why we saw a lot of literature that suggested that vitamin D lowered severity of disease in patients that got COVID-19,” Hokeness says.
A vitamin D deficiency has also been linked to increased risk for the development of osteoporosis, fractures, and muscle weakness. Some ongoing work suggests that low levels of vitamin D can impact the circulatory system and lead to increased risk of heart attack in people with underlying conditions while additional data suggest vitamin D is important to maintain proper cognitive functions.
“Folks who live in areas where available sunlight is low or is seasonal are more at risk for vitamin D deficiency. As you age, your ability to absorb vitamin D decreases, so older folks are more vulnerable,” Hokeness says. “Melanin slows the absorption of ultraviolet B rays (UVB) rays into the skin, so people with darker skin do not make as much naturally from sun exposure. Other conditions such as obesity or chronic conditions involving the intestinal tract are also at risk of malabsorption.”
Hokeness shares that there are several ways for your body to get or generate vitamin D — with sun exposure acting as the leading method.
“When the skin absorbs UVB rays from the sun, it triggers a biochemical reaction in the skin that converts a type of cholesterol into vitamin D3, which is the active form that gets transported to the bloodstream for use,” says Hokeness, adding that some experts suggest 15 to 30 minutes of sun exposure daily for optimal levels.
Certain foods — including egg yolks, milk, cheeses, and fatty fish — can also help since they have higher vitamin D levels; however, it’s important to note that you likely won’t get an efficient amount of vitamin D through diet alone since the foods that are rich in the nutrient are not diverse.
Another way is to take supplements — though recommendations vary.
“Some experts suggest everyone should take a supplement, especially if you fall into one of the at-risk categories such as infants, older adults, people with darker skin, or people who do not spend much time outdoors or have access to plentiful sunshine,” Hokeness says. “Vitamin D is available both over the counter and as a prescription, so I would suggest talking to your healthcare provider to see what your levels are and what supplements may be necessary.”
Vitamin D has also been touted as something that could potentially slow biological aging. Noting that aging is a complex process, Hokeness explains that vitamin D is essential for promoting bone and muscle integrity as well as a critical component in maintaining a healthy immune system, all of which play a role in aging.
On a cellular level, says Hokeness, cells have a biological clock that is determined by the length of telomeres (caps of DNA on the chromosomes that don’t have information necessary for development — essentially excess information). These caps are like the plastic pieces at the ends of your shoelaces that help to protect the integrity of your laces and prevent them from unraveling. Every time a cell divides, a part of the telomere gets cut off, so cells that have short telomeres are older, and shorter telomeres have been linked to aging.
“Several recent studies have shown that vitamin D can preserve telomere length and slow biological aging in cells, with one study suggesting up to three years off the cellular aging clocks,” Hokeness says. “There are, however, benefits to cellular aging and maintaining natural processes as older cells are normally tagged for cell death, which is important because older cells are more prone to errors in replication, which can be linked to cancer.”