Health Effects of Vitamin D

When we were asked about Vitamin D, most of us would know where we can actually get it for free. That’s right, I mean free, zip, nada. You guessed it… from the sunshine, our dearly beloved sun.

In this topic, we are going to explore how Vitamin D is so crucial for our health in countless ways, how much vitamin D do we need, where can we find and get it, and how important it is to our overall well-being.

What is Vitamin D?

Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 and vitamin D2. You can also purchase vitamin D3 and vitamin D2 online by clicking here, please. Thank you so much.

Vitamin D is called calcitriol, or sometimes cholecalciferol (vitamin D3), because it is calciferous (“carrying calcium around”) and a sterol (a type of steroid hormone).

Vitamin D is a nutrient your body needs for building and maintaining healthy bones. That’s because your body can only absorb calcium, the primary component of bone when vitamin D is present.

Vitamin D also regulates many other cellular functions in your body. Its anti-inflammatory, antioxidant and neuroprotective properties support immune health, muscle function, and brain cell activity.

Where Can You Get Vitamin D?

1. Our Beloved Sunshine

Vitamin D is primarily obtained from your body’s response to the sun’s UV rays when they penetrate your skin.

The amount of vitamin D your skin makes depends on many factors, including the time of day, season, latitude, and skin pigmentation.

Depending on where you live and your lifestyle, vitamin D production might decrease or be completely absent during the winter months. Sunscreen, while important to prevent skin cancer, also can decrease vitamin D production.

You don’t need to devote hours a day to sun-worship; recommendations range from 7-30 minutes per day over a large portion of your body. Studies have found that people with dark skin pigmentation may need up to sixfold more sun exposure than people with light skin to get the same vitamin D3 production in their skin.

Many older adults don’t get regular exposure to sunlight and have trouble absorbing vitamin D. If your doctor suspects you’re not getting enough vitamin D, a simple blood test can check the levels of this vitamin in your blood.

2. Food

Vitamin D isn’t naturally found in many foods. Vitamin D is found in certain types of fatty fish, e.g., halibut, salmon, (For more information on benefits of salmon, please click here. Thank you so much), and mackerel, animal organ meats like liver, and in very small amounts in eggs and dairy products.

Most foods containing vitamin D, including dairy milk, are fortified with it, meaning that the nutrient is added to them as a supplement. You can find vitamin D in fortified cereals, orange juice, and much plant-based milk, and it will be noted on the ingredients list.

The only plant-based foods that naturally contain vitamin D are some types of mushrooms, which contain it in the form of vitamin D2. Mushrooms produce vitamin D similar to how humans do when our skin is exposed to sunlight. The vitamin D content of mushrooms can be increased either by exposing them to direct sunlight or using UV lamps during their growing process.

3. Supplements

The most reliable way to raise your vitamin D levels is to take it as a supplement. There are two main forms of vitamin D: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). These two types of vitamin D are not equal when it comes to raising your serum vitamin D status. Both are effectively absorbed into the bloodstream, but your liver metabolizes them differently. Vitamin D3 appears to be much more effective in raising blood vitamin D levels than vitamin D2.

Vitamin D Supplement

Vitamin D can be found as a supplement on its own or as part of a multivitamin. It’s also added to a number of omega-3 fatty acid supplements.

Most supplements come in the form of vitamin D3, or cholecalciferol. However, most D3 supplements are not manufactured from vegan sources.

Instead, many come from animal products such as lanolin, which is a greasy substance produced by sebaceous glands of sheep and found in their wool. Still, vegan vitamin D3 supplements are becoming increasingly widespread.

These are usually made from lichen, an organism that arises from algae or cyanobacteria.

Vegan vitamin D2 supplements are also available but not usually recommended because they’re not as reliable when it comes to raising serum vitamin D levels. Plus, vitamin D2 appears to be more prone to degradation over time.

Breastfed Babies

Note that the American Academy of Pediatrics recommends all breastfed babies receive a daily dosage of 400 IU of vitamin D soon after birth to maintain their levels. This is because vitamin D is not transferred well through breast milk.

The babies generally shouldn’t be exposed to too much sunlight. Formula-fed babies don’t typically need this supplementation because infant formula is fortified with the vitamin D they need.

Taking a multivitamin with vitamin D may help improve bone health. The recommended daily amount of vitamin D is 400 international units (IU) for children up to age 12 months, 600 IU for people ages 1 to 70 years, and 800 IU for people over 70 years.

1. Micellized Vitamin D

While many vitamins D supplements come in gel, oil, or capsule form, there are also liquid dropper options called micellized vitamin D3. Micellization of vitamin D3 appears to improve its solubility, absorption, and bioavailability.

Which explains why a miscible form of vitamin D3 may actually be more effective in raising serum vitamin D levels than a fat-soluble version.

A 2016 study published in the Journal of Pediatric Endocrinology and Metabolism examined the effects of either 60,000 IU of fat-soluble vitamin D3 per month with milk or 60,000 IU per month of water-miscible vitamin D3.

The study lasted for six months and included 180 healthy kids, ages 13-14 years old. They found that the miscible form resulted in a significantly greater increase of serum vitamin D levels among the study participants.

2. Vitamin D and Vitamin K2

Research also indicates that vitamin D3 is best absorbed when paired with the nutrient vitamin K2. High blood levels of vitamin D — a potential problem for anyone taking D3 supplementation — can lead to excessive calcium accumulation in the blood, contributing to calcification of the blood vessels.

Vitamin K2 helps make sure that calcium is used in the bones instead of ending up in the arteries where it doesn’t belong.

Once the vitamin D has done the job of making sure the calcium you consume hits your bloodstream, vitamin K activates a protein called osteocalcin. This protein makes sure that the calcium that’s in your bloodstream winds up where you want it to go — in your bones and teeth.

Bottom line: You don’t want to be deficient in vitamin K if you’re taking vitamin D. For this reason, many people take their vitamin D and K together.

Guidelines for Vitamin D Levels

In 2011, the widely respected Endocrine Society issued a report which concluded: “Based on all the evidence, at a minimum, we recommend vitamin D levels of 30 ng/ml, and because of the vagaries of some of the assays, to guarantee sufficiency, we recommend between 40 and 60 ng/ml for both children and adults.” (That one is pronounced “nanograms per milliliter.”)

However, writing for the New England Journal of Medicine in 2016, several leading epidemiologists and endocrinologists stated that in their opinion, we are over-screening for vitamin D deficiency and unnecessarily treating individuals who are actually fine. Based on their analysis, a more appropriate cutoff for vitamin D deficiency would be much lower — 12.5 ng/ml.

This leads to another question, which is maybe what we should have been asking all along. What is optimal? Apparently, most people can survive with blood levels as low as 12.5 ng/ml. But is that what’s best?

Here too, there is controversy. But a growing body of research is finding that the optimal blood levels of vitamin D are above 30 ng/ml, while other studies conclude that 40-60 ng/ml is the preferred range.

10 Health Benefits of Vitamin D

1. Cancer. Findings on the benefits of vitamin D for cancer prevention are mixed. Research has shown that having higher serum levels of vitamin D is associated with a lower cancer incidence.

In fact, a 2019 meta-analysis of prospective cohort studies published in Nutrients looked at 16 studies involving 101,794 participants to determine the relationship between serum vitamin D levels and risk of cancer diagnosis and mortality.

The researchers concluded that with each 20 nmol/l (that’s pronounced “nanomoles per liter,”) increment increase of 25- hydroxyvitamin D (another name for calcidiol) concentration, the risk of developing cancer dropped by seven percent.

More studies are needed to determine whether vitamin D supplementation may reduce the risk of certain cancers.

2. Cognitive health.

Research shows that low levels of vitamin D in the blood are associated with cognitive decline. However, more studies are needed to determine the benefits of vitamin D supplementation for cognitive health.

3. Inherited bone disorders.

Vitamin D supplements can be used to help treat inherited disorders resulting from an inability to absorb or process vitamin D, such as familial hypophosphatemia.

4. Multiple sclerosis.

Research suggests that long-term vitamin D supplementation reduces the risk of multiple sclerosis.

5. Osteomalacia.

Vitamin D supplements are used to treat adults with severe vitamin D deficiency, resulting in loss of bone mineral content, bone pain, muscle weakness, and soft bones (osteomalacia).

6. Osteoporosis.

Studies suggest that people who get enough vitamin D and calcium in their diets can slow bone mineral loss, help prevent osteoporosis and reduce bone fractures. Ask your doctor if you need a calcium and vitamin D supplement to prevent or treat osteoporosis.

7. Psoriasis.

Applying vitamin D or a topical preparation that contains a vitamin D compound called calcipotriene to the skin can treat plaque-type psoriasis in some people.

8. Rickets.

This rare condition develops in children with vitamin D deficiency. Supplementing with vitamin D can prevent and treat the problem

9. It may help prevent and manage type 2 diabetes.

Having adequate vitamin D levels appears to be helpful in the management of type 2 diabetes as well. In a 2018 review published in Nutrients, researchers found that when serum vitamin D levels among people with type 2 diabetes were increased, their insulin resistance was reduced.

10. It may protect your body against viral infection.

Vitamin D has recently been highlighted as a key player in the strength of our immune systems, especially when it comes to fighting off viral infections.

In a 2020 study, researchers examined the mean vitamin D levels among populations from 20 European countries as well as the documented cases of COVID-19 and the subsequent mortality rates from the virus. They found a potential correlation between lower vitamin D levels and higher incidence of COVID-19 risk and mortality.

Additional Studies

An additional Spanish study on COVID-19 outcomes used vitamin D to treat patients already hospitalized for the disease. A total of 76 patients in the study were given the immunosuppressant hydroxychloroquine and the antibiotic azithromycin. Fifty of them were also given oral calcifediol (a vitamin D3 analog) daily, while 26 were not.

Of the 50 patients treated with calcifediol, only one required admission to the ICU (2%), while of 26 untreated patients, 13 required ICU admission (50%), and two died (8%). Although this was a small sampling of participants, the results were statistically significant when it came to reducing the severity of the disease.

These studies suggest that both screening for vitamin D deficiency and possibly using it as a supplementary treatment could play an important role in pandemic-related public health.

Other studies tell us that addressing vitamin D deficiency could also help protect against other viral illnesses, like seasonal influenza.

Getting Your Vitamin D Levels Checked

There are certain individual factors that can increase your risk of being vitamin D deficient. Some of these include:

  • Not eating fatty fish (since they are the main source of dietary vitamin D);
  • Being of advanced age;
  • Having limited or inconsistent outdoor sun exposure;
  • Having high melanin levels in your skin (generally, this accompanies dark skin pigmentation);
  • Having medical conditions that can limit fat absorption;
  • And being obese.

If you fall into any of these categories, checking your vitamin D levels is especially important.

Getting your vitamin D blood levels checked isn’t difficult. The test can be done with a pinprick of blood. This could give you very useful information. If you decide to take a significant dose of supplemental vitamin D (over 2,000 IUs per day), you may want to check your blood levels again after a few months of doing so to see if or how things have changed.

Studies have shown that each additional 100 IU of vitamin D3 you consume per day will raise your blood vitamin D levels by 1 ng/ml (2.5 nmol/l), on average.


There are also options to check your vitamin D at home, using a finger prick test. These can be easily obtained and done without a doctor’s prescription, such as the EverlyWell Vitamin D Test.

Simply conduct the test in the comfort of your own home (which you will temporarily make marginally less comfortable by drawing blood from your fingertip), and ship it using the prepaid shipping label, where it will be evaluated in a test lab by a physician.

Your results will be uploaded to a secure online platform within one to two weeks of receipt.

As in all things: Use your own best judgment. And where appropriate, consult with a qualified healthcare professional about your specific health needs.

Please let us know in the comments:

  • How much time do you spend in the sun?
  • Do you know if you have a vitamin deficiency? If so, Have you ever been tested for vitamin D deficiency?
  • Are you taking any vitamin D supplements now?

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Information on this site is not intended to diagnose, treat, cure, or prevent any disease. We encourage you to do your own research. Seek the advice of a medical professional before making any changes to your lifestyle or diet.

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