Do you know how to optimize your vitamin D levels for every season?
A growing body of knowledge shows that, at optimized levels, vitamin D functions as a hormone rather than a vitamin, with numerous notable effects on the body.
These effects include support for:
- Healthy immunity
- Healthy mood
- Targeted support for over 2000 genes
- Healthy bone formation
- Healthy glucose metabolism
- Musculoskeletal comfort
- Heart health
- Healthy skin
Many health experts consider the benefits of vitamin D to be one of the most important health discoveries of the past 100 years. In this video newsletter, I’ll share new research on vitamin D deficiency – which affects 87% of Americans – and walk you through how to safely increase your levels.
History of Vitamin D Deficiency
Vitamin D deficiency causing devastating bone-softening effects was reported as far back as the 1600’s. Originally treated with cod liver oil in the 1800’s, it wasn’t until the 1930’s that vitamin D deficiency was discovered as the cause.
Though called “vitamin D,” it is not really a vitamin, but a hormone. In fact, at optimized levels in the blood, the active form – known as calcitriol – is now understood as the most potent secosteroid hormone in the human body. At optimal levels its effects may extend far beyond bone support, showing responsibility for many health-promoting processes in the body.
Vitamin D “Overflow”
About ten years ago, researchers discovered that people who live in climates where natural sun exposure was the greatest experienced greater longevity. In northern climates, studies show up to 61% of Americans are vitamin D deficient, going up to 87% in the winter months (1)(2).
For the past 80 years it was believed that vitamin D was only important to the body for regulating calcium and protecting the bones. At levels below 50ng/ml, this is vitamin D’s main role. However, new research reported by the Vitamin D Council has shown that higher levels of vitamin D may have a much greater role to play. For example, when vitamin D3 levels are between 50-80 ng/ml the excess calcitriol (secosteroid hormone form of vitamin D) heads towards the cells – not the bones – where it then targets over 2,000 genes (about 10% of the human genome) in the human body.
It is this “overflow” of calcitriol that has created such a worldwide stir about the pervasive role of optimized vitamin D. At lower levels of sun exposure and vitamin D, this overflow simply doesn’t happen. The role of excess calcitriol in the cells – and the great importance of these findings – is only now being understood.
No Sun = No Fun
Fifty thousand years ago, humans lived predominately in climates around the equator. Clothing was minimal and sun exposure was constant. As we migrated north, we endured sunless winters, wore more clothes and adapted to living indoors – away from the sun.
Today, we live, sleep, eat and drive indoors away from the vitamin D-rich UVB sun rays. In latitudes north of Atlanta (33°N), the UVB (vitamin D making sun rays) simply do not exist from November through March, making these months an emotional endurance event for many. Seasonal mood disturbances and feeling low in the winter months is often found to have a connection with low serotonin levels, which may be related to lack of sunlight (2).
It is the UVB rays that convert the cholesterol (7-dehydrocholesterol) on the skin into D3 (cholecalciferol). According to the US News Report, UVB rays are only available when the UV Index is at 3 or above, which doesn’t happen in the winter for most of America. You can check the UV Index in your area.
D3 versus D2
The D3 form of vitamin D has been shown to have the highest absorptive affinity and less toxicity in the human body compared to the more popular vitamin D2 (ergocalciferol) (3). For this reason, vitamin D3 will store longer in the fats cells and help us endure a long, UVB-deficient winter.
Vitamin D2, which absorbs into the body 70% less effectively than vitamin D3 (4), was long thought to be the most active source of vitamin D supplementation. It is still used to fortify foods such as milk and orange juice and is the main pharmaceutical form of vitamin D support, though many pharmacies are now switching to vitamin D3 supplementation. Vitamin D3 is primarily derived from the sun, but is also found in cod liver oil and some fatty fish.
Native people commonly got their vitamin D3 in the winter by eating organ meats, which are generally rich in the fat soluble vitamins including vitamin D.
How to Get Vitamin D3 from the Sun
During the summer months, the UVB rays are the strongest between 10am – 2pm. For most people, 10-15 minutes of direct sunlight on unprotected skin during these hours will be enough to manufacture about 10,000 – 20,000 IUs of vitamin D3. Get just enough sun to turn your skin slightly pink. Darker-skinned people will have to get more sun to optimize their vitamin D levels.
It takes about an hour for the cholesterol on your skin to convert to D3 and then to be absorbed. So if you work out in the sun and then take a shower, you might be washing off all that precious vitamin D you just manufactured on your skin. If you can, wait at least an hour before rinsing off. Many animals get their vitamin D by licking their fur after being in the sun— the oil on their skin and fur has combined with the UVB rays to make vitamin D3.
How Your Body Uses Vitamin D3
From the skin, the vitamin D3 (cholecalciferol) heads to the liver, where it is converted to calcidiol (25 hydroxyvitamin D). This is the form that circulates in the blood and is most accurately measured on a blood test.
From here, the calcidiol heads to the kidneys where it is converted to calcitriol (1,25-dihydroxyvitamin D), the most active form of vitamin D, which circulates to every tissue in the body.