Healthy Vitamin D
functions of vitamin d
Vitamin D is a somewhat special, fat-soluble vitamin, in the sense that it is the only vitamin that the body itself can make. Vitamin D is produced inside body via the skin when ultraviolet rays from sunlight trigger its synthesis. However, for people residing in high latitudes, having a dark skin color, older age, being inside a lot, living in smoggy environments the diet is important to get enough vitamin D. Sources of food which are high in vitamin d are scarce.
>1 billion people in the world have low vitamin D levels. This is found in all ethnicities and age groups.
The active form of vitamin D, calcitriol, has a broad effect on many body processes. This is also apparent from the multitude of tissues in the body in which the vitamin D receptor occurs. It is estimated that vitamin D regulates directly or indirectly, via activation of the vitamin D receptor, between 100 and 1200 genes.
SOURCES OF FOOD HIGH IN VITAMIN D (PER 100 GRAM):
Shrimp 3,8 µg
Sardines 12,5 µg
Egg 0,5 µg
Mush-D Mushrooms 15 µg
Reasons for low levels
Seasonality: During the winter months the UV-B rays from the sun do not enter our atmosphere anymore. However, we need especially UV-B rays to build vitamin D in our skin. Thus, we cannot build own vitamin D between October and March on the northern hemisphere (above 37th parallel north) and between April and September on the southern hemisphere (below 37th parallel south). During this time we need to get it throug nutrition or supplements.
Living inside: Especially when you work inside or go to school you spend the majority of your everyday life inside. But even after work we often just chill and watch TV or Netflix. That's not how we get our daily vitamin D...
Geographic location: The further away from the equator, the angle of the sun changes and is less intense. read our blog post about the 37th parallel, because this latitude plays an important role in vitamin D production.
Skin protection: Skin protection is very important in areas where the sun is very intense. We do not want to tell you to start tanning without sunscreen, but wait 5 minutes until you start using it.
Smog:When air pollution and smog are present, less UV radiation reaches the earth.
Clouds: do usually block UV rays, particularly the UV-B. On a really overcast day, they can stop 70 to 90% of the UV-B from reaching the surface.
Cities: high buildings are prevent sun shine reaching our skin.
Age and pigment: elderly people and people with a darker skin need more uvb light to be effective
Clothing: covered clothing prevents uvb light to be effective.