Having spent the past 10 days in the sunny and warm mediterranean, I’ve managed to more than replenish my vitamin D intake, as well as get a nice tan! Vitamin D, together with omega-3 (read about it here), and magnesium are arguably the most important and essential micronutrients (and hence its nickname vital vitamin D!).
Vit D is vital as it helps our bodies absorb other nutrients better, with two of those being calcium and phosphorus (which are important for bone health). It also helps with the restoring and maintenance of calcium in our bones, so naturally with lower levels bones can become weak and fragile.
If you’re wondering how much inspo my trip gave me, clearly it is a lot. There’s a lot more to come, lots of creativity, ideas and new things comings! :)
However, like everything you can get too much of it. Vit D (like vit A, E and K) is fat-soluble, i.e., they dissolve in fats and oils and are stored in your liver and fatty tissue. So you do need fat to absorb those vitamins when consuming them, but of course as it’s stored in that manner you can get v high levels and not be able to get rid of it.
On a side note, speaking of vit A lately, I’ve been obsessed with carrots, make them into ribbons and add greek olive oil, salt, and vinegar and you have a super food of a salad!
☀️ The sun doesn’t magically give you the vitamin D, but it’s needed for its synthesis. When your skin gets exposed to ultraviolet B (UVB) rays and they go through the skin, they convert 7-dehydrocholesterol (this is naturally present in your skin) into pre-vitamin D3. Then pre-vitamin D3 get converted to vitamin D3 (cholecalciferol) through a heat-dependent process, and here the heat you get from the sun also helps. So, once D3 is formed, it goes through your liver and then your kidneys and it undergoes through hydroxylation reactions (in organic chemistry terms oxidation happens and a C-H bond gets converted to a C-OH bond). First one is in the liver, where D3 becomes 25-hydroxyvitamin D [25(OH)D] and then in the kidneys where the biologically active form of vit D is formed: 1,25-dihydroxyvitamin D [1,25(OH)2D], aka calcitriol. Calcitriol is the compound that plays a role in our health (bones, immune system, teeth etc).
Now that we’ve understood the process of the sun and the production of vit D, there are some limitations to it. Not everyone will react in the same way and produce as much vit D. Your skin affects how much is produced, darker complexions need longer exposure as the melanin in your skin does not allow for as much absorption of UVB. When you’re exposed to the sun also plays a role, UVB are most intense during midday and summer months, so the further away you’re from the equator and shorter winter days means you’re probs not getting adequate exposure. Another blocker is sunscreen use, the use of it blocks the passing of the UVB rays and hence the production. And lastly, age is also a factor, the older you are the less vit D you can produce. But the good news, is that you can easily supplement with minimal risk.
The figure above, shows what influences in increasing and decreasing your vit D amount. A 2023 meta-analysis of 7.9 million participants did indeed conclude that globally people are vit D deficient, the studies ranged from 2000 to 2022. And of course, this also increases the global burden of disease in combination high an increasing obese population, meaning even less vit D is absorbed. 1
I don’t know about you, but personally whenever I am under the sun I feel better mentally too - it may be that I am a tanner version and I enjoy that, or just my mediterranean genes feeling at home. I recently came across a tweet, that did state that vit D is also an anti-stress nutrient. So maybe, there truly is something about exposure to sun and hence vit D creation.
The study which those results were extracted from also noted a decrease in blood pressure, meaning a healthier heart. Another review also supported the same results, and that regardless of the vit D levels, exposure to sunlight had major benefits for cardiovascular health. 2
Remember, how at the start I mentioned vit D is important for bone, immune system, and teeth health? Well the same twitter account also commented on a study reporting that vit D protects against cavities.
Small edit: I forgot to mention the relationship between vit D serum concentration and incidence of orthopaedic post-op infection, a study carried out by my good friend Alexander Zargaran, which concluded that higher levels were linked with lower incidence of infection.3
Evidently, vit D is truly essential in more than one ways alongside sunshine itself. Even if you live in a sunny country, the chances that you get enough sun exposure are low as most of us tend to spend the majority of our day behind a screen. So, the next time you see the sun out take a walk during your lunch break or even take your next meeting outside (where appropriate ofc, no CEO meetings in that manner pls). And during the cold and gloomy months (which seem to still be here in London), do supplement, it’s not that expensive and the upside of it is much greater than the not doing so!
I hope you enjoyed, thank you for taking some time out of your day to read my posts! See you next week! :) 💛
Cui, Aiyong et al. “Global and regional prevalence of vitamin D deficiency in population-based studies from 2000 to 2022: A pooled analysis of 7.9 million participants.” Frontiers in nutrition vol. 10 1070808. 17 Mar. 2023, doi:10.3389/fnut.2023.1070808
Weller, Richard B. “Sunlight Has Cardiovascular Benefits Independently of Vitamin D.” Blood purification vol. 41,1-3 (2016): 130-4. doi:10.1159/000441266
Zargaran, Alexander et al. “The Relationship Between Serum 25[OH]D Concentration and Orthopaedic Infection: A Case-Control Study.” Orthopedic research and reviews vol. 12 121-125. 24 Aug. 2020, doi:10.2147/ORR.S252616