Photo by Oskaras Verbickas on Unsplash
This week a friend asked me why they had low vitamin D levels, despite it being winter now, they had olive skin and would often take winter holidays to top up their tan. It didn't make sense.
Conversely I am from Northern Europe and am not blessed with dark olive skin, I am pale, wear hats and zinc regularly, even with this said my vitamins D levels are within the normal range.
The human body is such an amazing machine and has developed its own way to regulate vitamin D intake – its pigmentation (the colour).
Our skins have evolved to be darker the closer we are to the equator and the level of exposure to UV rays increases. The darker the skin the darker the pigmentation and its ability to avoid damage.
It has been measured in the Fitzpatrick study that those of us with the darkest skin pigment need 6 times more UVB exposure to produce the same levels of pre-vitamin D3 than those with the lightest.
I used to live in one of the hottest places in the world, the temperatures would often reach 50 degrees celsius (122 degrees fahrenheit), the sun would be unbearable and the humidity levels often topped 90%. You couldn't even sweat to cool yourself.
I would wake early to exercise before the sun was high in the sky, and the heat got turned up, to make sure I got my dose of vitamin D.
Surprisingly on my medical that year I was told I was deficient in vitamin D and should be supplementing.
So why, even with pale skin, was I still not getting enough vitamin D?
Photo by Michael Starkie on Unsplash
Wavelengths
There are two types of sunlight:
UVA 315 – 400nm – generated early in the morning and at dusk, does not convert to vitamin D but can cause premature aging and skin damage.
UVB – 290 to 315nm – generated around midday when the sun is higher in the sky, converts to vitamin D.
For 7 months of the year, my morning exercise meant I was just absorbing UVAs and no vitamin D generating UVBs.
Our vitamin D begins as a hormone in the oil of our skin called 7-dehydrocholesterol. 7-dehydrocholesterol is created from cholesterol, cholesterol is widely villainised by the western pharmaceutical industry and misunderstood.
When the UVB rays hit this hormone in our skin it gets converted to pre vitamin D3.
The pre vitamin D3 is converted by the heat of the body into vitamin D3. This is the same vitamin D3 you find in supplements although a lot more bio available.
Vitamin D3 is then converted into calcidiol. Cacidiol is like the warehouse for your vitamin D and is the level that is measured on your blood tests.
Finally the calcidiol gets released from storage and converted to calcitriol in the kidneys, this is the active form that regulates our immune system, mood and bone health.
We can support this process by not excessively stripping the oils in our skin through excessive washing and avoiding hormone disrupting skin products.
"Everybody's Free (to avoid sunscreen)."
A play on the 90's song
When we apply sunscreen it blocks 98% of UVB and UVA rays and decreases our production of pre-vitamin D3 by 90-100%.
Commercial sunscreen contains oxybenzone which is a known hormone disruptor , mimicking estrogen and having anti-androgenic effects, which can stunt sexual development and affect your reproductive system.
Oxybenzone's chemical structure includes double bonds, making it highly susceptible to oxidative stress. When exposed to sunlight—which, funnily enough, is exactly when we apply sunscreen—it can generate free radicals that may cause DNA damage, potentially increasing cancer risk.
Does this sound like something we should be putting on our children's skin?
Photo by Paweł Mizia on Unsplash
How Much Sun?
Everyone should try to get 30 minutes of sun exposure per day when the sun is high in the sky and UVB levels are increased (think 10am-2pm).
If you are sensitive to to the sun then wear a hat and get exposure from your arms and legs.
If you must wear sunscreen then apply a little zinc oxide on your nose and cheeks – you will often see surfers wear it like war paint. If you are not so keen on this look then there are also clear versions available. Zinc oxide is non toxic and does not disrupt hormones. It will block both UVA and UVB so use sparingly to ensure you don't limit your UVB exposure.
Don't stop your morning walk! Even though morning light lacks UVB and won't boost your vitamin D, it contains blue light wavelengths that suppress melatonin production, helping to set your circadian rhythm and regulate your body's internal clock for better sleep at night. Make sure you don't wear sunglasses during your walk as we absorb the blue light through our eyes.
Should You Supplement Vitamin D?
For those of us in high latitude countries with less sunshine or spend a lot of time indoors we may still struggle to maintain optimal vitamin D levels, you can be tested to confirm if you are deficient. You can increase levels through diet and supplementation.
Avoid vitamin D2, this is the cheap version of vitamin D that cereal and dairy producers often "fortify" their products with. It is worse than useless, it has a low bio availability and will compete with our star vitamin D3.
Vitamin D3 can be found naturally in oil fish: sardines, mackerel, anchovies, salmon, and herring (think SMASH). You can also take a D3 supplement.
Photo by Joshua J. Cotten on Unsplash
Finally, I want to address the reports of vitamin D3 being rat poison. Excessive vitamin D3 intake means we have too much calcitriol circulating in our bloodstream causing hypercalcemia (too much calcium). Hypercalcemia can mean we pass calcium stones and suffer from nausea and vomiting.
In a study rats were given 15,000IU per kg of vitamin D3 which caused organ failure due to hypercalcemia. To put this into prospecting this toxic dose would be the equivalent to me taking over a million IUs which is 1000 times what I take each day.
(A friend of mine left a bowl of vitamin D3 for a rat which greedily gobbled it all up and I can confirm that it is incredibly effective).
If you are tested and found to be deficient then 1000iu of vitamin per day has been found in this study to raise levels of calcidiol by 100%. I would recommend using a liquid dropper version of a vitamin D3 supplement, capsules are often poorly absorbed and need to be taken with a meal containing fat. Choosing a supplement with K2 included which will mean that the body is able to better utilise the vitamin D3 and avoid hypercalcemia.
About the Author: Nicholas Walton-Cole (NA. Dip)
