Top Vitamin D Benefits

Smiling woman looking up against trees at park during autumn

You probably know that vitamin D is crucial for bones because it is required for calcium absorption — but that’s just the tip of the iceberg.

Did you know vitamin D has been linked to reduced cancer risk, reduced risk of Alzheimer’s, and even helps prevent diabetes? Keep reading to discover even more surprising benefits of the commonly referred to “sunshine vitamin.”


The Sunshine Vitamin

Although you might think that the sunshine vitamin is simply that — a vitamin that we get by soaking up the sun — there is much about this supposed vitamin that remains misunderstood. First, vitamin D is not a vitamin. In fact, it’s more of a steroid hormone, similar to estrogen, testosterone, and cholesterol. Second, vitamin D does not refer to a single nutrient but a group of natural steroid chemicals, there are hundreds of different steroids found in plants and animals.

Because of its hormone structure, vitamin D gets cells ready for other important hormones (like the ones mentioned) to do their work. It also helps the body absorb calcium, iron, magnesium, and zinc in the intestines. But vitamin D itself can’t do anything useful until it is converted to an active form within the body called vitamin D3.


9 Evidence-Based Benefits of Vitamin D

The following are the top science-backed benefits of vitamin D:

Supports Healthy Bones

Bone health is dependent on the dynamic process of remodeling. Vitamin D, along with other nutrients like calcium and hormones, helps bones to constantly be rebuilt as they naturally break down. Vitamin D enables calcium and the mineral phosphate to be absorbed to mineralize bones. Without enough of the sunshine vitamin, bones can become thin, brittle, or misshapen.

Osteoporosis is often associated with not eating enough calcium-rich foods. But a deficiency of vitamin D also contributes by reducing calcium absorption. Osteoporosis is, therefore, a long-term effect that slowly occurs with insufficient vitamin D. This is especially true in those who have difficulty exercising (and building muscle), in postmenopausal women, and people on steroid therapy.

Vitamin D deficiency is also associated with greater incidence of hip fractures. In a 2008 review of women with osteoporosis hospitalized for hip fractures, 50% had low vitamin D. The researchers concluded that calcium and vitamin D therapy was paramount to prevent osteoporotic fractures. Daily supplementation with at least 800 IU of vitamin D and 500–1,000 mg/day of calcium was recommended to reduce fracture risks by 25–70% in the elderly. A 2010 study went on to say that for optimal leg function to prevent falls at least 800 IU/day vitamin D is needed.

Reduces Cancer Risk

Long-term studies have shown that adequate vitamin D can reduce cancer risk and reduce fractures when taken with calcium. Many cancer research agencies and institutions now stress the importance of getting adequate vitamin D. This is especially true for those with a genetic predisposition for certain cancers like breast, prostate, skin, lung, pancreatic, and colon cancer. Breast and colon/colorectal cancers have been found to be the most closely related to lack of sunshine. And men, too, are at risk; more research found that men who lacked sunshine had a higher incidence of cancer and died sooner as a result.

New York nutrition specialist Michael Greger MD, FACLM, stated (in 2016) that scientists reviewing 56 trials involving 100,000 people who took vitamin D supplements for four years found that they lived four to five years longer than those who didn’t. And specifically, they lowered the risk of dying from cancer. Research also shows that both incidences of and death rates from certain cancers were lower among people living in southern latitudes where sunlight exposure is high, compared to those living in northern latitudes.

In studies of cancer in mice, vitamin D was found to slow or prevent cancer because it:

  1. Promoted cellular differentiation (so cells become specialized in order to perform a specific function rather than reproduce exactly the same)
  2. Decreased cancer cell growth
  3. Stimulated cancer cell death
  4. Reduced tumor blood vessel formation (which reduced the tumor’s ability to live)

Read more about the latest studies involving calcium and vitamin D reducing the risk of cancer. Pretty senior lovers hugging with joy

Reduces Alzheimer’s Risk & Lowers Alzheimer’s-Related Fractures

Did you know that vitamin D-deficient people are twice as likely to develop Alzheimer’s and dementia? A 2015 article states that an international team conducted research studying 1,600 seniors for six years. They found that those who were severely deficient in vitamin D were far more likely to develop Alzheimer’s or dementia than those who had adequate levels. Participants who were mildly deficient had a 53% increased risk, and those severely deficient had a 125% increased risk.

Interestingly, people who have Alzheimer’s or dementia are more likely to break a bone. How are they related? Alzheimer’s is associated with increased hip fracture risk because many Alzheimer’s patients are homebound, sunlight-deprived, and older. This is doubly troublesome since, with aging, less vitamin D is converted to its active form, and decreased bone density is linked to reduced vitamin D (from supplements and sunlight). A 2010 study of nursing home residents with dementia found sun exposure to be extremely limited at less than 15 minutes per week.

A person with dementia is up to three times more likely to fracture a hip than a cognitively intact older adult. This is because vitamin D receptors in the brain may protect and detoxify messenger cells that enable the brain to send and receive signals to other areas of the body (like those making muscles work and legs walk.) These vitamin D receptors are reduced in Alzheimer’s and dementia patients. Also, an increase in parathyroid hormone is found in Alzheimer’s patients with hip fractures, but not in Alzheimer’s patients that haven’t broken bones. Since vitamin D helps balance this hormone, scientists feel low vitamin D further increases risks due to hyperparathyroidism.

Decreases Cardiovascular Disease

Too little sunshine puts your heart at risk! Evidence is growing that vitamin D deficiency increases the risk of heart disease, congestive heart failure, high blood pressure, and chronic blood vessel inflammation associated with the hardening of arteries. Low levels are also linked to heart disease risk factors such as obesity, diabetes, and atherosclerosis (the formal term used to describe hardening of the arteries).

Even though women are more often the target of this outcome, a 2008 study showed that lack of vitamin D increased heart attacks in men. Another study done in the same year found that not only is low vitamin D associated with higher risk of cardiovascular disease, it’s linked with death due to all types of illnesses, including heart disease.

Why does vitamin D affect blood pressure? Vitamin D increases an enzyme called renin which regulates the amount of blood and other fluid that goes through veins and arteries. Renin also balances the amount that arteries constrict. So, too low levels of vitamin D and renin can negatively affect blood pressure. This was found to be true of women with high blood pressure and low vitamin D. Vitamin D Benefits Inforgraphic

Protects Against Diabetes

What causes diabetes? Type 2 diabetes has usually been linked to poor diet. However, when scientists analyzed 21 studies from around the world involving 76,220 participants, there was another link. There was a significant association between lack of sunshine and/or vitamin D supplements with a high risk of type 2 diabetes. This was shown across a broad range of low vitamin D levels.

The elderly may be most at risk. A 2011 study of older subjects found that getting enough vitamin D protects against type 2 diabetes. The association between lack of vitamin D and type 2 diabetes may be because it affects glucose levels and β-cell function. These directly relate to insulin secretion and insulin resistance.

Unfortunately, the link is also found in kids with type 1 diabetes. Vitamin D-deficient children have a far greater prevalence of pre-type 1 diabetes and type 1 diabetes.

How does vitamin D affect insulin? Both abnormal vitamin D levels and abnormal glucose levels are associated with high inflammation. It may be that vitamin D deficiency increases inflammation, and this inflammation is detrimental to the ability to secrete insulin. This could be because it reduces the availability of vitamin D receptors in the body which are required to make insulin.

Supports Healthy Pregnancies

The benefits are stacking up that a mother needs to give her child vitamin D even before she/he is born. In 2007 the Canadian Pediatric Society announced that pregnant women and nursing mothers should take a daily supplement of 2,000 IUs. Vitamin D deficiency can lead to serious repercussions in a developing fetus.

Experts from research institutes worldwide called for international agencies to “reassess as a matter of high priority” outdated dietary recommendations for vitamin D. This was meant for both the mother and unborn child.

Research from 2013 states without adequate vitamin D taken during pregnancy, preeclampsia, gestational diabetes, and cesarean section are more common. And newborns risk low birth weight, rickets, hypocalcaemia, asthma, and type 1 diabetes. Vitamin D deficiency during pregnancy also affects neurodevelopment and the baby’s immune system, even though it only shows up decades later. This study also says that vitamin D helps a woman get pregnant in addition to maintaining normal pregnancy, supporting fetal growth through the delivery of calcium, secreting placental hormones, and reducing inflammation.

Healthy children need 1,000 IU of vitamin D per 25 pounds of body weight and D3 levels should be more than 50 ng/mL year-round. Some research shows that vitamin D deficiency may contribute to the development of some diseases, including schizophrenia, autism, respiratory tract infection, newborn seizures (usually due to low calcium), heart failure, atherosclerosis, brain tumors, epilepsy, and viral pneumonia.

According to the Vitamin D Council, damage to unborn children done by deficiency may be permanent and cannot be fully reversed by taking vitamin D after birth. Vitamin D deficiency during pregnancy endangers the mother’s life and puts the child’s brain and immune system at risk. Yet prenatal multivitamins have little effect since they only contain 400 IU of vitamin D3. The Council says, “over 95% of pregnant women have D3 levels that indicate chronic substrate starvation.”

Want some evidence? Watch the testimonial of Dr. Amie Harper who took AlgaeCal Plus during her pregnancy. woman with flu symptoms

Boosts Immunity

Vitamin C is the classic go-to for an immune boost when you’re feeling under the weather, but vitamin D plays a critical role in keeping your immune system strong. Like vitamin C, supplementing with it reduces the likelihood of getting the flu according to 2010 research, especially in schoolchildren with asthma.

Even more recent research finds that vitamin D also helps prevent all types of autoimmune diseases. Why? It is called a “natural immune modulator,” regulating many immunological functions affected by inflammation. Low vitamin D may contribute to chronic inflammatory illnesses including lupus, rheumatoid arthritis, and cirrhosis. Vitamin D prevents autoimmune diseases including multiple sclerosis and inflammatory bowel disease (IBD) because of its effects to activate our powerful immune-boosting T lymphocyte cells and cytokines.

Combats Depression

If vitamin D is called the sunshine vitamin, it stands to reason that one too many dreary days with cloud-filled skies could affect your natural vitamin D intake. And you’d be right to think that.

Low levels of vitamin D have been linked to Seasonal Affective Disorder (SAD) and depression.

Researching 12,594 patients at the prestigious Mayo Clinic, scientists found that low vitamin D was definitely associated with depressive symptoms. Another study published in the American Journal of Clinical Nutrition evaluated 81,189 women ages 50 to 79 and found that women with higher vitamin D intake from food had less depression. They said it’s because vitamin D can affect the function of our two “happiness neurotransmitters,” dopamine and norepinephrine.

Vitamin D supplements, not just sunshine and food, can improve depressive symptoms. Supplementing vitamin D in overweight and obese people with depression offers significant improvements in mood after one year of taking a higher dose supplement. This might be due to the fact that there is a decrease in parathyroid hormone with vitamin D.

Historically, seeing the sun was cause for celebration. It meant food could grow, and conversely, not seeing the sun often meant food was becoming scarcer. Ancestral memory may play a role in why spending time outdoors makes people feel better.

But research also shows that seasonal affective disorder is not just in your head. Symptoms may be due not as much to missing the sun’s brightness as to changing amounts of vitamin D3, which affects serotonin levels in the brain.

What about other negative moods? Although vitamin D is not believed to affect anxiety directly, lack of it may be correlated with higher stress and anxiety. People who experience seasonally patterned depression often feel anxiety and symptoms related to anxiety such as irritability, antisocial behavior, insomnia, and reduced sex drive.

Reduces Rheumatoid Arthritis

It’s a bit of a vicious circle that people with advanced arthritis often don’t go outside enough, and yet it is lack of sunshine that may partly cause their discomfort. Vitamin D deficiency and its relationship with inflammation have been linked particularly with rheumatoid arthritis.

A 2014 study from Oxford University found definite links between vitamin D and increased disease, inflammation, and bone loss in patients with rheumatoid arthritis. Swollen, tender joints, joint pain, and morning stiffness were associated with low levels of vitamin D. And rheumatoid arthritis patients with osteopenia or osteoporosis had even lower amounts.

Vitamin D has been found to balance inflammation by regulating proinflammatory cells. This is why it might help prevent inflammatory diseases including rheumatoid arthritis. New evidence suggests supplementing decreases risks. Also since low vitamin D increases poor outcomes of acute infections, supplementing could help heal inflammation and infections.

vitamin D benefits - vitamin D rich foods - non dairy milk

Vitamin D Sources

Worldwide, almost 50% of the population is insufficient in vitamin D. While sunlight is a major source of vitamin D, the reality is, the majority of us are not getting enough time in the sun.

After the sun, the next logical sources to turn to is food or supplements. Yet to reach the new proposed Reference Dietary Intake (RDI), which is in the 1000s of IUs per day, you would have to consume five times more dairy products (that’s 10 glasses of milk daily) and oily fish such as salmon every day. To increase your intake safely, especially when sunlight is scarce, it makes sense to supplement.

What offers rich vitamin D? Learn all about the best sources on our Vitamin D sources page.


Best Vitamin D Supplement

For many of us, vitamin D supplementation is vital. And as you’ve read, although it is necessary for bone health, it benefits the body in so many more ways. The most important thing to keep in mind if you opt for supplements is that you only want natural vitamin D3 (cholecalciferol). This is the type of vitamin D found in foods like eggs, organ meats, cod liver oil, and fish. Synthetic and highly inferior vitamin D2 is not recommended.

It is well established that vitamin D3 is the best-absorbed form and the one used in bone and cancer research. And it’s the type required for calcium absorption which will aid in overall bone, joint, and dental health.

Several studies comparing the effectiveness of D2 versus D3 prove this. As mentioned earlier, humans convert sunlight into D3 naturally, and it stays in our bodies longer than D2.

So in light of what you’ve learned about vitamin D, what’s a reliable vitamin D supplement? Well, AlgaeCal Plus has 1600 IU of vitamin D3 in a daily dose of 4 capsules. Since vitamin D3 works closely with calcium, magnesium, and other vitamins and minerals for bone health, AlgaeCal Plus also supplies all of these nutrients that work closely as a team. In fact, you get over 70 nutrients that build new bone, instead of just one.

Vitamin D Takeaways

So what have we learned? We know the active form of vitamin D is important for your aging skeleton. We also know vitamin D3 has potent properties unrelated to this because it is found in tissue throughout the body. These include its highly researched anti-cancer and immune-boosting characteristics, which also make it a top “vitamin” for increased vitality and anti-aging.

Vitamin D deficiency has long been associated with ailments like rickets, cardiovascular disease, and asthma, in addition to bone-breaking osteoporosis. Getting enough of it may also help prevent rheumatoid arthritis, type 1 diabetes, multiple sclerosis, and hypertension. Vitamin D ensures healthy cell growth (and proper cell death so that cells don’t become tumors). It is needed for neuromuscular function, and it reduces inflammation.

Just some areas of the planet get enough sun exposure to satisfy human needs. Ultraviolet B rays are absorbed by the skin and converted to vitamin D. It’s first metabolized in the liver and then kidneys to activate it as D3. But many of us don’t get enough due to latitude, seasons, skin pigmentation, aging, sunscreen use, and living with double-paned glass windows.

If you’re one of those people who struggle to get enough vitamin D on a daily basis, look to a well-rounded, plant-based supplement that not only meets your RDI of vitamin D but contains all the other helper nutrients it needs to perform at its best.


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