We know Vitamin D – otherwise known as the Sunshine Vitamin – for its protective effect on bone health, as it contributes to calcium absorption. In fact, more and more studies are also linking it to the good efficiency of the immune system.
We have always been told to stay in the sun – with due precautions, of course – because our body produces Vitamin D thanks to exposure to the sun's rays : its importance has always been linked to the effect it has in fixing calcium to the bones , a very important action both in preventing rickets in children and in protecting the elderly from the action of osteoporosis. This Vitamin, which in its activated form actually acts as a hormone, is however proving that it is not limited to this very important function.
Vitamin D, Immune System and Inflammation
Acting as a hormone , Vitamin D affects the functioning of different organs and interconnected systems within the body: this is why it acts as a real anti-inflammatory and helps strengthen the immune system, thus giving the body the resources needed to protect itself from external attacks. Although studies from this point of view are not yet definitive, the results obtained so far seem to lead everyone in this direction.
Where do we find Vitamin D ? Most of it, as mentioned, is produced by the skin during exposure to UVB rays from the sun (it is not called the Sun Vitamin for nothing). A fat contained in the epidermis, when exposed to UVB rays, is in fact transformed into Vitamin D and from there it passes into the bloodstream and then to the liver and kidneys, where it is activated.
Vitamin D is produced mostly by our skin during exposure to sunlight, but it can also be found in some foods. Supplementation is recommended whenever a deficiency is found and especially in the cold months, when we tend to spend less time outdoors and cover up more. Its action also seems to be important for the immune system.
As for nutrition, apart from foods that are fortified with it, we can find it in fatty fish, egg yolk and liver, although the main source is always exposure to the sun. Vitamin D taken through food is absorbed at the intestinal level: from here, as for that produced by the skin, it passes into the bloodstream and is then activated by the liver and kidneys.
Insufficient exposure to the sun – especially likely in our latitudes in the autumn and winter months – can cause low levels of Vitamin D in the blood, with all the consequences that this entails: it is therefore better to monitor your levels of this important nutrient and, if they are too low, integrate it to ensure all the benefits. But be careful not to overdo it: even too high levels of Vitamin D can be harmful to our body, better to stay in the upper part of the range considered normal.
How Vitamin D Works on the Immune System
The action of Vitamin D on the immune system would depend on its ability to activate T-lymphocytes, i.e. the cells responsible for recognizing foreign bodies harmful to our body and eliminating them. Vitamin D would act on the formation of specific receptors on the surface of T-lymphocytes, making them capable of identifying foreign bodies and therefore responding appropriately to external attacks.
