I’ve been seeing so many posts being so very excited for spring, and a rather common talking point is how much the sunshine gives you vitamin D and how healthy that is for you. And it makes me wonder how many people understand how vitamin D even works in the body.
Sunshine does not, in fact, provide you any vitamin D whatsoever. It’s an interesting fact that sunshine actually converts the cholesterol in your skin into Vitamin D.
According to health.howstuffworks.com;
“When UVB rays hit your skin, a chemical reaction happens: Your body begins the process of converting a prohormone in the skin into vitamin D. In this process, a form of cholesterol called 7-dehydrocholesterol (7-DHC), naturally found in your skin, absorbs the UVB radiation and gets converted into cholecalciferol. Cholecalciferol is the previtamin form of D3. Next, the previtamin travels through your bloodstream to your liver, where the body begins to metabolize it, turning it into hydroxyvitamin D, which is also known as 25-hydroxyvitamin D or 25(OH)D. The kidneys then convert the 25(OH)D into dihydroxyvitamin D, also called 1,25-dihydroxyvitamin D or 25(OH)2D — this is the hormone form of vitamin D your body can use”
Which basically means that UVB rays (or, unfiltered sunlight) reacts with cholesterol in our bodies to make a substance that enters our blood, which our organs then process into vitamin D!
Additionally of interest, Vitamin D is really important in doing certain things in the body like absorbing calcium, fighting infections and generally keeping your blood flowing and your muscles healthier. Perhaps, though, the most exciting thing about vitamin D is it’s potential to prevent cancer when found in high levels. It tends to line up surprisingly well with what we’ve seen in increased cancer rates in a modern world (we spend much less time in the sunshine than we used to as a species), and while correlation is not causation (and many factors including genetic contribute to cancer), many cancer research institutes are taking it very seriously.
Interestingly, we can see exactly how this effects our bodies in chickens and eggs that we eat. There’s a reputable and highly-cited study done by Mother Earth News that used an independent lab and tested dozens of egg samples from pastured poultry. Their findings made complete sense with what we know about how bodies process sunlight. Chickens exposed to more sunlight produced eggs with significantly lower cholesterol and 3 to 6 times as much vitamin D as CAFO style eggs.
So it only makes sense that chickens raised in sunshine produce better eggs. It’s the same reason we try to get sunshine ourselves. And the same applies to other animals as well, like pigs or cows. Animals raised outdoors in full sun have higher levels of vitamin D in their bodies and lower levels of cholesterol, which they pass on to their byproducts (milk, cheese, eggs, even their offspring) and their meats (ham, bacon, steaks).
So if you ever wonder why your great-grandpappy lived to be 95, worked like a horse until the day he died, all the while eating eggs and bacon for breakfast every day and never getting cancer… You may only need to look up at the sky. The answer could have been right above you the whole time!