In the article on vitamin D3, we wrote about 50% of people on Earth suffering from a deficiency of this vitamin. In our climate is easy to understand that it must be vitamin D supplementation in autumn, winter or even spring, but what to do in the summer? How to safely complete the deficiency of vitamin D3 in the Sun?
It is not without reason that vitamin D3 is called "vitamin of the sun". When the skin is exposed to the sun's rays, UVB rays combine with cholesterol in the skin cells, so that they provide energy for the formation of vitamin D3 by your body. Vitamin D3 has many roles in the body and is essential for his health. One of the tasks he does is to increase the absorption of calcium and phosphorus in bones - two minerals that are crucial for maintaining strong and healthy bones. In addition, science combines low levels of vitamin D3 with serious diseases such as osteoporosis, cancer, depression, muscle weakness or even premature death.
Unfortunately, it is difficult to find sufficient amounts of vitamin D3 in food, which Poles consume every day. In addition to egg yolks popular with us, good sources include fish oil, salmon, tuna, beef liver and sardines, but you would have to eat them every day to satisfy your vitamin needs.
Another bad news is that UVB rays do not pass through window panes, so even if you're working close to a window, you're still exposed to a vitamin D3 deficiency.
12:00 o'clock, especially in summer, is the best time to catch the most sunshine. Why? The sun is then at the highest point and the UVB rays then work the hardest. Thanks to this you need less time for your body to produce enough vitamin D3. Not to be groundless: a 2010 study, published in The Journal of Investigate Dermatology, showed that 13 minutes in T-shirt and shorts 3 times a week for 6 weeks on the Sun is enough to make up for vitamin D3 deficiency. Do you think that the study was conducted in sunny Spain or California? Nothing more wrong! The results come from the United Kingdom, i.e. less sunlit climate than ours. As you can see, you do not have to lie on the beach for two weeks to gain energy! On the contrary - as you will see after reading the next item, this tactic will hurt you more than it will help you.
However, first let's get back to the research on the best ways to supplement vitamin D3. Another study shows that 30 minutes on the sun at midday gives the same amount of vitamin D3, which will take 10-20,000 units. This is a shock dose that will last for many days! We anticipate your doubt - the research was carried out in Oslo, Norway, a country famous for its ubiquitous darkness and harsh winters.
Subsequent studies confirm that going to the Sun at noon is not only more effective in increasing the level of vitamin D3 in the blood than in the afternoon, it is also safer. Researchers have found that contact with the afternoon sun may increase the likelihood of serious skin cancers.
Shock and disbelief? Usually people with darker skin tones from birth or due to holidays in warm countries meet with admiration and poorly concealed jealousy. However, in the context of supplementing vitamin D3 levels, a dark skin tone is a disadvantage, not an advantage. Let's start from the beginning.
The shade of your skin depends on the pigment called melanin. People with dark complexion usually have more of it than those with a light complexion. Melanin, however, has more roles than just giving color - it protects the skin against damage caused by the sun. Melanin acts as a natural sunscreen, absorbing UV rays and protecting against burns and skin cancer. Unfortunately, this fact also shows that people with a lot of melanin, or dark complexion, have to spend more time on the sun, so that their skin produces the right amount of vitamin D3.
How much more?
 Holick MF. Biological Effects of Sunlight, Ultraviolet Radiation, Visible Light, Infrared Radiation and Vitamin D for Health. http://ar.iiarjournals.org/content/36/3/1345.full
 Rhodes LE, Webb AR, Fraser HI. Recommended summer sunlight exposure levels can produce sufficient (> or =20 ng ml(-1)) but not the proposed optimal (> or =32 ng ml(-1)) 25(OH)D levels at UK latitudes. https://www.ncbi.nlm.nih.gov/pubmed/20072137
 Cicarma E, Porojnicu AC, Lagunova Z, et al. Sun and sun beds: inducers of vitamin D and skin cancer. https://www.ncbi.nlm.nih.gov/pubmed/19667143
 Moan J, Dahlback A, Porojnicu AC At what time should one go out in the sun? https://www.ncbi.nlm.nih.gov/pubmed/18348449