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Into the Heart of Vitamin D

The sunshine vitamin’s potential impact on our cardiovascular health


The celebrated “sunshine vitamin,” otherwise known as vitamin D, is commonly praised for its ability to support overall bone strength and immune function, but emerging research also continues to illuminate its benefits related to heart health.

“Traditionally, [vitamin] is known as something that’s good for the bones, because it helps improve calcium absorption in the bloodstream,” explains Laura Brass, ND. “But it's been discovered over the years to benefit almost every system in the body—from the immune system to the cardiovascular system.”


The power of vitamin D

This powerhouse vitamin has many essential roles in the body. One of its long-hailed benefits is supporting calcium absorption in the gut for optimal bone health. It also promotes overall muscle strength and repair, and our immune system depends on the nutrient to ward off unwelcome bacteria and viruses.

Recent research also indicates its potential impact on reducing major cardiovascular events among older adults, such as heart failure and hypertension, and suggests a deficiency in vitamin D could raise the risk factor for these diseases.

“Vitamin D is known to help from an arterial perspective,” says Caitlyn Keates, ND. “It helps the blood vessel lining and blood to flow more freely through that lining, thereby reducing a lot of the inflammation that’s within the arterial wall of the heart.”


“D” for deficient

Yet despite the wide-ranging benefits of this nutrient, vitamin D deficiency has been identified as a public health problem around the globe.  “When we see patients in practice, I’d say nine times out of 10, we see some sort of deficiency in vitamin D in their bloodwork,” explains Keates.

While our body synthesizes vitamin D when our skin is exposed to sunlight, sunscreen (an obvious skincare essential) can hinder absorption by as much as 90 percent. Other factors such as age can also lessen the amount of the vitamin our skin absorbs. A person in their eighties, for instance, will produce about half as much vitamin D compared to someone in their twenties.

It also turns out that few foods naturally contain the nutrient. Some of the best whole food sources include fatty fish like salmon and trout, fish liver oils, egg yolks, and some mushrooms (especially varieties that have been treated with UV light to increase their vitamin D content).

“We also have a lot of gastrointestinal concerns here in North America, and the gastrointestinal system is where we absorb our vitamin D,” says Keates. “I’ll often dose vitamin D, and the patient’s values won’t budge until we address what is going on within the gut itself.”


Deficiency and aging

When vitamin D is lacking, our bodies absorb less dietary calcium, which leads to low calcium stores, and increases the risk of fractures, especially among older adults. This is especially relevant for women during and after menopause.

“Bone density becomes an issue as we go through menopause because we don’t have the same level of estrogen, which helps keep our bones mineralized and strong. So vitamin D is critical,” Brass says.

And when it comes to heart health, low vitamin D levels can also be linked to high blood pressure and heart disease, risk factors that increase as we age.


Nutritional supplement

Since adequate vitamin D levels are difficult to obtain from sun exposure and food sources alone, a supplement is often recommended by health professionals. However, not all forms of vitamin D supplements are created equal.

For starters, Brass encourages people to prioritize a supplement containing vitamin D3 (versus D2) which has been shown to be a more effective form of the nutrient.

Keates suggests that a liquid-based supplement may be a more suitable option, depending on your particular lifestyle habits and circumstance. “Vitamin D is fat soluble, so it needs a carrier oil to be absorbed properly,” she says, explaining how an oil-based supplement already provides that fat source to ensure the vitamin is bioavailable.


Heart of the matter

While research is still emerging, and the connection between vitamin D and heart health is not yet conclusive, Brass says it’s about looking at the nutrient’s significance more holistically.

“Vitamin D has such a far-reaching impact,” she says. “Yes, it’s going to support the health of your blood vessels and inflammation, but it’s also going to improve your immune health and reduce your risk of colds and flus; it has so many benefits.” Consider it a big picture perspective we can all take to heart.


Better together

While vitamin D is integral to our overall well-being, recent research indicates it performs best when paired with another nutrient: vitamin K2.

●                   Vitamin K2 is a fat-soluble vitamin found in some animal products and fermented foods.

●                   The nutrient is difficult to obtain from food alone, so a supplement is often recommended.

●                   It helps ensure the calcium absorbed from vitamin D is properly funnelled into our bones.

●                   It can help reduce the risk of cardiovascular disease by preventing calcium buildup in the arteries.

●                   Taking vitamin D and K2 together is especially important for older adults.


Ray of light

When it comes to vitamin D’s impact on heart health, one 2023 study, published in the British Medical Journal, found the rate of cardiovascular disease among 60- to 84-year-olds to be 9 percent lower when taking a vitamin D supplement compared to those given a placebo (the rate of heart attacks was 19 percent lower in the vitamin D group).


Daily dose

How much vitamin D in supplement form is right for you? Keates says the correct daily dosage will fluctuate for each person, and will depend on factors such as age, weight, and level of deficiency (which requires a blood test to determine). Your health care practitioner, whether a physician or naturopath, can help guide you in the right direction.


This article was originally published in the February 2024 issue of alive magazine.



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