Get the Fuck in the Sun - VITAMIN D Masterclass
Vitamin D is known as the sunshine vitamin for a good reason. This essential nutrient is completely unique because our bodies can manufacture it when our skin is exposed to sunlight.
However, an estimated 40% of Americans are deficient in vitamin D. That’s a huge proportion. And it has serious implications for our health. Vitamin D is involved in all sorts of different processes in our bodies, from building strong bones to preventing disease.
Scientists are increasingly uncovering new ways that this magical substance supports our physical and mental health.
In this post, I’m diving deep into vitamin D. Learn how our bodies make vitamin D, the essential roles it plays in our health, and why so many of us are deficient.
What Is Vitamin D?
The name vitamin D is a bit misleading because it isn’t technically a vitamin at all. In fact, vitamin D is a fat-soluble steroid hormone.
What makes vitamin D unique is that we can manufacture it when our skin is exposed to sunlight. When the UVB rays from the sun hit our skin, they kickstart a complex set of processes that turn the cholesterol in our skin into the bioactive form of vitamin D, which is called calcitriol.
I know – we’re more used to hearing of cholesterol as a villain because of its role in cardiovascular disease. But there are different types of cholesterol. In this case, we’re interested in one called 7-dehydrocholesterol.
When this type of cholesterol interacts with UVB rays, it is transformed into vitamin D3 (also known as cholecalciferol).
D3 is probably a familiar name from supplements and fortified foods. There’s another form of vitamin D too, which is called D2. More about this in a moment.
However, vitamin D3 isn’t bioactive, which means our bodies can’t use it yet. Before it is turned into the usable form, calcitriol, it needs to undergo two further processes. The first takes place in our livers and the second in our kidneys.
Finally, we end up with a form of vitamin D that our bodies can actually use.
What Are the Benefits of Vitamin D?
One of the best-known roles of vitamin D is keeping our bones strong and healthy. It helps our guts to absorb calcium and phosphorous from our food, which are essential for bone growth and repair.
When we don’t get enough vitamin D, we’re at risk of developing issues with our bones, such as rickets (which affects children), osteomalacia (the adult version), and osteoporosis.
But strong bones aren’t the only benefit of getting enough vitamin D. Studies show a link between our vitamin D levels and many other aspects of our health, including:
1. Our ability to fight upper respiratory diseases (including Covid 19?)
There’s evidence to suggest that increasing our vitamin D levels helps our immune systems fight off upper respiratory diseases. These include widespread illnesses like the flu and the common cold.
Of course, one upper respiratory disease that has been on everyone’s minds lately is Covid 19. And several studies have pointed to a correlation between low vitamin D levels and an increased likelihood of being hospitalized from Covid, including this research from Italy and this cross-country study.
So, why hasn’t this link been more publicized? Unfortunately, many of the same factors that are known to increase our vulnerability to Covid (age, weight, general health, diet) also affect our vitamin D levels, so scientists can’t be sure that the correlation means higher levels of vitamin D protect against Covid.
Considering that we already know vitamin D helps to protect us against other upper respiratory diseases and we know that it plays other vital roles in our body, it seems like a no-brainer to make sure we are getting enough, especially at a time when a healthy immune system is so important.
2. The risk of cardiovascular disease
Heart disease is the leading cause of death in America. But vitamin D may help to reduce the risks. Many observational studies have found a link between vitamin D deficiency and an increased chance of having a stroke or a heart attack.
3. The likelihood of getting (some) cancers
Researchers noticed that people in the Southern hemisphere were less likely to develop certain cancers, which prompted several investigations into the link between cancer and vitamin D. Although there’s still more work to do, there are some encouraging signs that vitamin D helps to reduce the chance of getting some forms of cancer.
4. Our mental health
As we increasingly understand the link between our guts and our brains, we’re uncovering more and more evidence about the role nutrition plays in our mental health. And it seems vitamin D is an important part of that picture.
Anecdotally, many of us notice that our moods drop when we get less sunshine. Clinical evidence backs this up – an evaluation of the evidence concluded there’s a link between low vitamin D levels and mental health issues such as depression.
5. Our sex drive
You read that correctly – vitamin D seems to be linked to sexual function and desire in both men and women. That’s likely down to both its effect on testosterone production and the way it influences our mood
How Can We Get Vitamin D?
Hands-down, the best source of vitamin D is sunlight. This accounts (or should) for 50%-90% of our daily vitamin D needs.
It is lucky that our bodies can make vitamin D themselves because there aren’t many other natural sources. Vitamin D3 is only found in a handful of foods, including egg yolks, butter, liver, and oily fish.
As for plants, normally a brilliant source of nutrients – they aren’t so great when it comes to vitamin D. Mushrooms do produce a form of vitamin D, but it is vitamin D2, not D3.
Our bodies can absorb vitamin D2. But we are less efficient at turning it into a form of vitamin D that we can actually use. According to one study, vitamin D3 is almost twice as potent as D2 for increasing our useable vitamin D.
This doesn’t mean eating mushrooms is useless for vitamin D – it just isn’t as effective as sunlight. Mushrooms do have plenty of other benefits, however, so there’s good reason to include them in your diet, especially if you are vegetarian or vegan.
Like animals, mushrooms can only make vitamin D when they are exposed to sunlight. So, you’ll only get the benefits if you find mushrooms that have been grown in UV light, or outdoors.
Many foods are fortified with vitamin D since so many of us are deficient. And you can also take vitamin D supplements. But again, it is important to be aware of which form of vitamin D you are taking.
Many fortified foods use vitamin D2 because it is cheaper to produce. But it doesn’t work as well to raise our vitamin D levels, so look out for supplements with vitamin D3 instead.
What Prevents Us from Getting Enough Vitamin D?
Sunlight, unlike most things, is still free. So, how is it that most of us are still not getting enough vitamin D?
Well, there are a few factors that can affect our vitamin D levels. These include:
1. Gut health
Although sunlight is the main source of vitamin D, diet does play a role too. To efficiently absorb vitamin D from your diet, you’ll need a healthy and well-functioning gut.
2. Liver and kidney health
As we saw at the beginning, turning vitamin D from the sun or your diet into its usable form requires processing by your liver and kidneys. If they aren’t functioning at their best, you won’t be able to produce vitamin D as easily.
3. Age
Sadly, our ability to produce vitamin D reduces as we age, which is why many older people are deficient in this vital nutrient.
4. Weight
Vitamin D is fat-soluble, so it can be stored in body fat. However, there’s a well-established link between obesity and lower vitamin D levels. It seems that carrying excess fat might interfere with the body’s ability to process and store vitamin D.
5. Melanin levels
Melanin plays an important role in protecting us from sunburn. It is why populations from countries with more sun tend to have darker skin and why we tan when we spend time in the sunshine. Unfortunately, melanin also interferes with vitamin D absorption, which is why people with darker skin are more likely to be vitamin D deficient.
Other than these, the major factors that affect our vitamin D levels are all to do with our level of exposure to the sun. People who live further from the equator get less sun, especially in the winter, and will likely need to take a supplement.
But even in the summer, many of us simply don’t spend enough time in the sunshine. Our busy lives often keep us indoors. Sitting by a sunny window won’t help – the UVB rays can’t get through the glass.
And when we are outdoors, we still aren’t getting the sunlight exposure we need. Why? Because the sunscreens we use to protect ourselves from sunburn and skin cancer also block the UVB rays we need to kickstart the vitamin D-production process.
Time to Get Out in the Sun
We need at least 20 minutes each day with 40% of our skin exposed to the sun to maintain the right levels of vitamin D. The exact number of minutes we need will vary depending on the time of day, season, where we live, and our melanin levels.
But overly strong sunscreens will prevent enough of those UVB rays from reaching our skin. Many sunscreens are also made with toxic ingredients, including oxybenzone, octinoxate, and homosalate, which are all endocrine disruptors. Check out my favorite sunscreen HERE and for kids HERE.
What can we do instead? First, learn to trust the sun again.
I’m not suggesting you spend all day in the blazing sun without any protection in the middle of summer. But be sensible about it – allow your skin some sunscreen-free exposure each day so you can get the vitamin D you need.
The time spent outdoors can do wonders for your mental and physical health, as well as your vitamin D levels.
When you need sunscreen, choose an appropriate SPF level that will protect you while still allowing some UVB rays to penetrate. And choose one without the harmful chemicals that can damage your health.
During the winter months, a good quality vitamin D supplement can help you replace some of the vitamin D you need while you can’t get out into the sun. Our bodies can also store vitamin D, so it is even more important to make sure you get enough sun exposure in the summer months.
Finally, look after your general health. Take care of your gut, take care of your organs. You need them to absorb and process vitamin D efficiently.
And FFS. Get out in the sun.