10 Surprising Benefits of Vitamin D

• Published March 26, 2025

• 95 Comments

Vitamin D, also known as calciferol, has been associated with various health conditions, ranging from sleep problems to neurotransmitter (serotonin) regulation. The prevalence of vitamin D deficiency among U.S. adults is approximately 35%, increasing to 61% in the elderly population. There are many Vitamin D benefits, some of which you may find surprising.

What is Vitamin D?

Vitamin D is an essential nutrient. It is a fat-soluble vitamin that dissolves in fats and oils, so they are absorbed into the bloodstream with dietary fat. It is not readily excreted like water-soluble vitamins. Instead, vitamin D is stored in the body’s fatty tissues and absorbed over time when dietary fats are absorbed.

Vitamin D2 is found in foods like tuna, salmon, cheese, beef liver, egg yolks and fortified milk and cereals. Vitamin D3, on the other hand, is the more potent and bioavailable form of vitamin D. It is synthesized in your skin when the skin is exposed to sunlight, making it the most natural and effective way to obtain vitamin D.

Vitamin D deficiency can develop for many reasons.

→ Diet does not supply enough vitamin D.
→ Skin is not exposed to enough sunlight.
→ Darker skin pigment absorbs less sunlight.
→ Some health conditions lead to a vitamin D malabsorption problem.
→ Liver disease or kidney failure causes deficiency due to inability to convert vitamin D to its active form.
→ Medications interfere with the ability to convert vitamin D or absorb vitamin D.
→ Following a vegan diet that does not compensate for the lack of consumption of foods with vitamin D.
→ Aging.
→ Genetics.
→ Obesity.
→ Smoking.

Besides sun exposure and food, vitamin D is obtained by taking dietary supplements.

What is Vitamin D Good For?

Vitamin D is essential to the quality of life in many ways, including some surprising ones. The role of this vitamin in maintaining good health is often underestimated. Following are 10 surprising vitamin D benefits.

1. Promotes bone health

Vitamin D plays a role in calcium absorption. A vitamin D deficiency can cause osteomalacia or osteoporosis. Osteomalacia is a condition in which bones and muscles are weakened because calcium and phosphorous are not deposited in adequate amounts into bones. Bones become soft. Osteoporosis is a disease in which bones become less dense and thinner but maintain their normal structure. In both cases, bones are more likely to break.

2. Supports a stronger immune system

Low vitamin D is correlated with a lower-functioning immune system. It is expressed on immune cells that can synthesize vitamin D, modulating the immune response.This vitamin may significantly impact innate (general defense system) and adaptive (responding activity) immune systems. It also may reduce susceptibility to infections, including respiratory infections.

3. Involved in sleep quality and regulations

Vitamin D is involved in the production of melatonin. Vitamin D is needed to break down tryptophan to make serotonin and to break down serotonin to make melatonin.

4. Improves muscle function

Researchers have reported a strong correlation between a sufficient vitamin D level and optimal muscle function. Increasing vitamin D reduces immune system overactivity and myopathy (diseases impacting skeletal muscles) and increases muscle protein synthesis and ATP (cell energy) concentration.

5. Deficiency may improve risk factors for cardiovascular disease

Vitamin D may not directly reduce cardiovascular disease, but low vitamin D has been linked to an increased risk. It is believed that vitamin D has a positive impact on the risk factors for cardiovascular disease. For example, low vitamin D has been linked to a risk of high blood pressure. Vitamin D metabolites bind to receptors regulating various factors, including cell production and oxidative stress.

6. Deficiency may improve type 2 diabetes

Clinical studies have found an association between low vitamin D and a higher risk of developing type 2 diabetes. Vitamin D has been found to lower the risk of insulin resistance, which means the body cannot appropriately respond to the insulin your body produces. Researchers suggest this may be one of the health benefits of vitamin D3 because it helps to lower the body’s overactive immune response. The risk for insulin resistance goes up when this response increases.

7. Associated with autoimmunity

Vitamin D deficiency is associated with increased autoimmunity actions and infection susceptibility. People with rheumatoid arthritis often have low levels of vitamin D. So vitamin D is associated with flare-ups of such disorders.

8. Supports a balanced immune response

Vitamin D plays a role in regulating the body’s immune activity. It assists with regulating the production of certain immune signaling molecules (cytokines) and may slow the activity of cells that contribute to immune overactivity. Many people with chronic disease have lower vitamin D status.

9. Supports women’s health through hormone regulation

Growing evidence shows a relationship between vitamin D and hormones in women. Vitamin D functions as a hormone and helps with the production of estrogen.

What is D3 good for? Vitamin D3 benefits for women include the expression of genes that play a role in estrogen biosynthesis. In fact, vitamin D has been found to significantly impact female reproductive health in positive ways, including concerning the menstrual cycle, the ability to get pregnant and pregnancy outcomes.

Vitamin D2 and D3 are both important to good health. However, vitamin D3 has been found to produce more of the active form of vitamin D. It may be better able to provide women with benefits like supporting bone density, the immune system and heart health. Levels of vitamin D3 also are more likely to remain stable after a dose.

Vitamin D is crucial for menopausal women’s and younger women’s health. Vitamin D alleviates genitourinary tract problems and regulates the growth of vaginal epithelial cells, two common issues associated with menopause.

10. May improve mood and support emotional health

There is increasing evidence that vitamin D may play a role in regulating mood. Low levels of vitamin D may interrupt serotonin production, which is the neurotransmitter that regulates mood and feelings of anxiety. Vitamin D may contribute to reduced feelings of stress or nervousness.

FAQs

Vitamin D: An Important Element of a Healthy Diet

Vitamin D receptors are found throughout the body and are involved in nearly all bodily systems. The ten benefits of vitamin D mentioned are not all of them. For example, studies have found that vitamin D supports brain cell health and may provide some protection against developing dementia or Alzheimer’s. Ensuring you get the appropriate vitamin D amount daily through diet, sunlight or supplements is crucial to maintaining good health. The first step is consulting with your healthcare provider for guidance on the amount of vitamin D to take.

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About the Author

Michael Levin

Michael Levin is a hemp enthusiast, a researcher, writer and editor in the cannabis space, experienced CBD user and educator. He believes dietary supplements can help improve our overall health and wellbeing.

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