Sun and vitamin D
A growing number of studies suggest that there is a link between vitamin D deficiency and various forms of cancer, rheumatoid arthritis, depression, schizophrenia and heart disease. A 2014 study published in the Journal of Internal Medicine even found that women who avoid the sun are twice as likely to die than those who sunbathe regularly.
The sun is our main source of vitamin D. Enjoy the sun, but make sure you do not burn. After all, this is harmful to the skin and increases the risk of skin cancer. It is important to find the right balance: sunbathing is healthy, but don’t overdo it.
Below you will find an overview of relevant information on optimal and safe vitamin D production from sun exposure.
1. The skin produces vitamin D more quickly when the UV index is higher. In the Netherlands this is mainly from mid-April to mid-September between eleven o'clock in the morning and three o’clock in the afternoon. On the website of the RIVM you can check the daily UV index levels in The Netherlands: http://www.rivm.nl/Onderwerpen/U/UV_ozonlaag_en_klimaat/ZonkrachtA study from the university of Tromso in Norway found that subjects with low levels of vitamin D, who live at a high latitude (68 degrees N.), are able to produce vitamin D from sunlight as early as in the beginning of march. In the light of this study, one can conclude that vitamin D production in the Netherlands is also possible during this period.
2. It is advisable to acclimatize the skin gradually to the sun without burning. Start with short exposures of a few minutes and slowly build up. There is no need to sunbathe for hours to get enough vitamin D. Your body stops producing vitamin D after a short period of time: when the skin turns the lightest shade of pink or darker. People with fair skin can experience this effect within minutes. According to research published in the medical journal The Lancet, people with dark skin need six times more sun exposure to produce the same amount of vitamin D as someone with fair skin.
3. A study published in the Journal of Internal Medicine revealed that women with normal sun exposure habits are not at significantly increased risk for melanoma. The study examined the sunbathing habits of 29.518 Swedish women for 20 years.
4. A balanced diet rich in omega-3 fatty acids and antioxidants can help to protect the skin against sun damage from the inside out. Also read: Nutrition against sunburn
5. Research published in The Journal of Clinical Endocrinology and Metabolism found that sunscreen with a sun protection factor (SPF) of 8 blocks the production of vitamin D by 95%. According to a study in the British Journal of Dermatology vitamin D production increases exponentially when thinner layers of sunscreen are applied to the skin.
6. More and more doctors and researchers are of the opinion that showering and bathing immediately after sunbathing washes away much of the vitamin D. So far there is no scientific evidence to support this theory.
7. As the skin ages, its ability to produce vitamin D decreases. A study published in the medical journal, The Lancet showed that a 70-year-old produces 75% less vitamin D than a 20-year-old.
8. Vitamin D created from sun exposure is prefered over supplements. The body automatically produces the right amount, without having the risk of overdosing. According to Vitamin D expert Dr. Holick, studies found that vitamin D produced from the sun lasts two to three times longer in the body.