Consider these facts: More than a billion people worldwide are Vitamin D deficient or insufficient.1<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3068797/>
This means that their blood levels of this important nutrient are less than 20 mg/dl (deficient) or between 20mg/dl and 29mg/dl (insufficient).
In 2009, researchers from Harvard and the University of Colorado revealed that 70 percent of whites, 90 percent of Hispanics, and 97 percent of blacks in the United States have insufficient blood levels of Vitamin D.
The study was published in the Archives of Internal Medicine.
Near the equator—in South Africa, Saudi Arabia, India, Brazil, and Mexico—estimates are that between 30 percent and upwards of 80 percent of children and adults who have minimum sun exposure are Vitamin D deficient or insufficient.
Vitamin D deficiency or insufficiency is the most common medical condition in the world with sometimes devastating, even fatal consequences.
These are not my words but the words of Dr. Michael F Holick, a pioneer of groundbreaking studies in Vitamin D deficiency.
Contrary to popular wisdom, Dr. Holick says, Vitamin D isn’t just for bone health. It is actually a hormone that plays a central role in metabolism and also in muscle, cardiac, immune, and neurological functions, as well in the regulation of inflammation.
Dr. Holick further adds that we have been brainwashed into thinking that exposure to sunlight is bad.
This is both unfortunate and untrue.
There is no substantiated scientific evidence to suggest that moderate sun exposure significantly increases the risk of cancer, even the most deadly form of skin cancer, melanoma.
In this article we will dicuss the following:
- What is Vitamin D?
- Benefits of Vitmain D
- Population at Risk of Vitmain D Deficiency
- Optimal Levels of Vitmain D
- Ways to Get More Vitamin D
- Conclusion and My Recommendation
What is Vitamin D?
Vitamin D, also known as calciferol, is a fat soluble vitamin, which means it can be stored in the body for a long time, just like vitamins A, E and K.
When exposed to sunlight, your skin produces vitamin D3 (cholecalciferol) and sends it to your liver.
From there, your liver changes it to a substance called 25(OH)D (calcifediol).
It then gets converted to 1,25(OH)2D (calcitriol), mostly in the kidneys.
This is the active steroid form of Vitamin D.
Did you know that Dr. Michael was responsible for isolating and identifying the major circulating form of Vitamin D in humans as well the active form produced by the kidneys?
The active form of Vitamin D travels through the body, affecting almost every cell.
Benefits of Vitamin D
One of the most vital functions of Vitamin D is regulating the absorption of calcium and phosphorous, which is important for normal growth and development of bones and teeth.
A study2<https://pubmed.ncbi.nlm.nih.gov/19523595/> published by CF Garland, et. al. concluded that raising the minimum serum 25(OH)D level to 40 – 60 ng/ml all year around would prevent approximately 58,000 new cases of breast cancer and 49,000 new cases of colorectal cancer each year!
These levels are also expected to reduce case-fatality rates of patients who have breast, colorectal, or prostate cancer by half.
There is also strong evidence for a protective effect of Vitamin D, not only against several types of cancer, but also against multiple sclerosis3<https://pubmed.ncbi.nlm.nih.gov/17179460/> and type 1 diabetes mellitus.4<https://pubmed.ncbi.nlm.nih.gov/15989379/>
Some studies5<https://pubmed.ncbi.nlm.nih.gov/18180395/> have revealed that the sunshine vitamin can also decrease chances of developing heart disease; however, evidence is still weak and further clinical and experimental studies are required.
Population at Risk of Vitmain D Deficiency
1) People who spend a lot of time indoors during the day. If you spend most days indoors at a desk job, try and go outside to get sun exposure. The beneficial UVB rays cannot enter through window glass, so also make sure to keep windows open when possible.
2) People with darker skin. “Your skin pigment is natural sunscreen,” says Holick. Someone with very dark skin needs up to ten times the amount of sun exposure as someone with a very pale complexion to make the same amount of Vitamin D.
3) People who cover their skin all the time or who apply sunscreen the moment they step out in sun. “A sunscreen with 30 SPF reduces the skin’s ability to make Vitamin D by a whopping 97 percent”, suggests Dr. Holick.
4) People that live in countries away from the equator (like Canada). Naturally, if you live farther from the equator in countries like Canada that get less sunshine, it’s best to take a D3 supplement to raise your Vitamin D levels.
5) Older people and obese people. The following study suggests that older people and obese people are at a higher risk of having a deficiency of this essential vitamin.
I highly recommend getting your Vitamin D 25(OH)D levels checked to see if you fall into either group discussed above (deficient or insufficient).
Optimal levels of 25(OH)D in your blood
Again quoting Dr. Holick: “The Institute of Medicine, including the Endocrine Society, recommends at least 20 for bone health. But there’s this area between about 21 and 30 that we consider to be an insufficient level. Most experts agree that if you’re above 30 nanograms per milliliter, this is a healthy level”.
Table for levels of 25(OH)D blood levels:
Less than 11: Severely deficient
21—32: Low Normal
66—101: High, but not toxic
Greater than 101: Toxicity Possible
Because of its variability in the assay, the recommendation from the Endocrine Society Clinical Practice Guidelines that looked at all the literature and made recommendations for prevention and treatment of Vitamin D deficiency for doctors is 40 to 60 nanograms per milliliter.
Here are two ways to get more Vitamin D:
The best way to get adequate Vitamin D is through moderate exposure to the sun during appropriate times. If possible, expose at least your arms, legs, and back for 15 to 20 minutes two or three times a week. You can put sunscreen on after twenty minutes to prevent excessive sun exposure, which may cause premature aging and increase cancer risk.
As noted earlier, the amount of Vitamin D you produce from sunlight depends on where you live, what time of day you are in the sun, and what color your skin is. The D-minder app is awesome for predicting your Vitamin D levels. It’s fun to watch your levels go up bit by bit once you go out in the sun and turn your app on. Try it now; it’s fun and healthy.
Elaborating on the timing of sun exposure, Dr. Holick states that you cannot make Vitamin D before 10:00 am or after 3:00 pm. To get maximum exposure to UVB rays, go out in the sun at around 1:00 pm.
Contrary to popular advice, UVA rays (which cause wrinkling and increase your risk of skin damage and cancer) are harsher in the morning and late afternoon, so make sure that you limit your exposure to the hours before 10:00 am and after 3:00 pm.
If you work a night shift or live in Canada or Iceland where there is no sun most of the year, taking a supplement can help ensure that you get enough Vitamin D.
I haven’t used any Vitamin D supplements (although there is some Vitamin D3 in my multivitamin), but I do trust Dr. Mercola’s advice and his products. He recommends a high-quality cod liver oil for Vitamin D supplementation. Remember that Vitamin D is fat-soluble, so it is possible to overdose, as it can accumulate over time and potentially become toxic.
This is extremely rare, however.
A note about Vitamin D and food: It’s close to impossible to get enough Vitamin D from food. For example, 100 grams of salmon has about 500 IU, and a whole egg has about 50 IU. To be in the optimal range (40ng/ml—65ng/ml) you will need at least a few thousand IU daily.
What do you think about this article? Have any questions or comments, let me know below!