Benefits, deficiencies, sources and supplements

You’ve probably heard people call vitamin D the “sunshine vitamin”, the one that the body created by exposure to UV rays and that, when you’ve had enough, can improve your mood. But the benefits of vitamin D, specifically vitamin D3, go far beyond a smile (although that’s very important). It actually plays a key role in bone health, the strength of your teeth, and the strength of your immune system. Keep reading to find out how.

    How does vitamin D work?

    “Vitamin D is a fat-soluble vitamin that is both a nutrient and acts as a hormone,” explains Melissa Perst, DCN, RDN, spokesperson for the Academy of Nutrition and Dietetics. Its main function is to help the body absorb and regulate calcium and phosphorous, ensuring they are available to strengthen bones and teeth, she adds. It also helps in the absorption of magnesium, which supports muscle and nerve function as well as energy levels.

    Vitamin D also boosts the immune system by inhibiting the production of inflammatory cytokines, a molecule that signals inflammation, explains Heather Mangieri, RDNsports and wellness dietitian in Pittsburgh, Pennsylvania.

    There are two main types of vitamin D—vitamin D2 and vitamin D3. Vitamin D2 naturally occurs in some plants, while vitamin D3 is found in some animals and is produced by human skin via exposure to sunlight. Mangieri explains that D3 is considered the most potent form of the vitamin because it “has been shown to elevate levels higher and for a longer period of time than D2.”

    Benefits of Vitamin D

    Ongoing research continues to uncover just how crucial vitamin D is for overall health. “It’s involved in many metabolic pathways, and scientists continue to study its role in heart disease, diabetes, depression, and multiple sclerosis, among others,” Mangieri adds. That being said, here are some of the ways that proper vitamin D levels can improve your overall well-being:

    strong bones

    Vitamin D deficiency, especially in the elderly, increases the risk of fractures and promotes weak and general weak bones, Prest says. “This condition is called osteomalacia and can cause bone deformities, pain, seizures due to low blood calcium, muscle spasms and dental abnormalities,” she adds. Also low in vitamin D increases the risk of developing osteoporosis or brittle bone disease.

    strong muscles

    Although further research on the relationship between vitamin D and muscle mass is warranted, some studies found that high levels of vitamin D were linked to improved strength.

    Improved immunity

    Due to its ability to regulate the production of inflammatory cytokinesVitamin D has been shown to help the immune system overcome bacterial and viral infections such as pneumonia and even COVID-19.

    Better heart health

    Vitamin D deficiency has been associated with heart disease and mortality from cardiovascular disease. However, more research is needed to determine if vitamin D supplementation can improve these conditions.

    Boosted mood

    Low vitamin D content has been scientifically linked to depression, and vitamin D supplements are sometimes used to treat it. However, more research is needed to confirm that supplements can reverse symptoms of clinical depression.

    Sources of Vitamin D

    Although vitamin D is found in certain foods, these are not foods that most people regularly put on their plate. “Fatty fish like salmon, tuna, mackerel, and trout, as well as fish liver oils, are some of the best natural sources,” Mangieri says. “Cheese, egg yolks, beef liver and mushrooms also contain small amounts.” Other foods like milk, yogurt, cereal, and orange juice are often fortified with vitamin D, which means the nutrient is added.

    “It’s hard to get enough vitamin D from food alone,” Perst admits. “We need to consume vitamin D and get some sun exposure to make sure our bodies have enough supplies.” That being said, soaking up the sun isn’t always easy.

    “Cloud cover, season, distance from the equator, pollution, skin pigmentation, age, and wearing sunscreen can all impact the amount of vitamin D your body is capable of producing,” explains Mangieri. In addition, there is the risk of skin cancer.

    Mangieri adds that the US Food and Drug Administration (FDA) recommended daily allowance of vitamin D for children and adults is 600 international units (IU). “While I fully encourage a diet-focused approach,” she says, “when it comes to vitamin D, a dietary supplement is often needed.”

    Vitamin D deficiency

    You only need to supplement with vitamin D if you know for sure your levels are low, which Mangieri says is hard to confirm without a blood test from a doctor. “Most symptoms are vague and can be easily overlooked,” she adds. “As a sports dietitian, I worry about vitamin D deficiency when I see an athlete complaining of fatigue, bone pain, muscle aches, or multiple bone fractures or injuries.”

    Other symptoms of a deficiency include muscle weakness and mood changes, according to the Cleveland Clinic.

    Dietary supplements are products intended to supplement the diet. They are not medicines and are not intended to treat, diagnose, mitigate, prevent or cure any disease.

    Vitamin D supplements

    You can get both vitamin D2 and vitamin D3 in supplement form. Vitamin D2 supplements are made by exposing yeast’s ergosterol to UV light, Perst explains, and vitamin D3 supplements come from exposing 7-dehydrocholesterol – obtained from the lanolin of sheep’s wool – to UV rays. “There is also an animal-free version of vitamin D3lichen-based,” she adds, which comes from algae.

    “For people following a vegan diet or avoiding certain animal products, they can contact the manufacturer of the dietary supplement to inquire about the ingredients of the product, and how it was obtained and processed,” explains Perst. It is also important to note that vitamins and supplements are not regulated by the FDA. If you need it, Perst recommends looking for a standalone vitamin D supplement over a multivitamin to make sure you’re getting enough nutrients.

    “Look for brands that have the USP verification mark on the label or that have been tested by third parties through programs such as NOTCertified SF for sport or an informed choice,” adds Mangieri. “By choosing supplements with these labels, you know that what is on the label is actually present in the product in the stated amounts.”

    Most importantly, Mangieri suggests having a conversation with your doctor or dietitian before starting the supplement. A professional, she says, can help you figure out how much to take.

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