It started exactly one year ago - the corona pandemic. It presented humanity with hitherto unknown challenges and thereby brought with it not only a great deal of uncertainty, but also a huge information chaos and a lot of misinformation. There was frequent speculation as to which measures would reduce the likelihood of infection with Covid-19 or avoid severe courses. And it was precisely in this discussion that a vitamin came up frequently - vitamin D. To this day, this vitamin is on everyone's lips. On the one hand, the sun vitamin is important for the health of bones and muscles. On the other hand, it contributes to the normal functioning of the immune system. And that is exactly the topic that is very relevant to all of us right now. This blog post is intended to give you the opportunity to acquire basic knowledge about this vitamin.
What exactly is vitamin D and what is it good for?
Vitamin D is a fat-soluble vitamin that is produced by the body when the skin comes into contact with sunlight. The human body is heavily dependent on the sun for this, as between 75% and 90% of the vitamin D in the body is produced in response to sun exposure, more specifically to UV-B radiation. Another 10-20% of the vitamin can also be ingested through food. However, it should be noted here that the concentration in foods containing vitamin D is very low and is therefore not sufficient for the complete supply of the organism! Especially in central European latitudes, a vitamin D deficiency can occur quite quickly, especially in winter - due to a lack of sunlight. Strong sun protection can also reduce vitamin D production in the body.
However, it is really important for the organism that there is a sufficient vitamin D level in the organism and that the requirement - if this is not the case - is also covered by supplements if necessary. Because the vitamin is responsible for a large number of functions in the body. Probably the best-known function is the support of bone metabolism. Among other things, vitamin D promotes the resorption - i.e. the absorption - of calcium and phosphate from the intestine and is also responsible for the incorporation of these substances into the bones. This means that the vitamin has a crucial role in bone mineralization! In addition, the vitamin is involved in a number of metabolic processes and in the formation of various proteins, as well as the control of certain genes.
But that's not all, because vitamin D also contributes to the normal functioning of the immune system. The vitamin may also play a role in the body's immune response to respiratory viruses (such as Covid-19), but the evidence here is still insufficient and therefore not clear.
Are there differences in the D vitamins?
Vitamin D belongs to a group of fat-soluble vitamins, the calciferols, which includes vitamins D1 to D5. However, there are significant differences in effectiveness between these subspecies. Because vitamin D3 differs from the rest of the D vitamins in that it is the only vitamin produced naturally in the body - the other D vitamins are therefore man-made vitamins. Vitamin D3 is advantageous in that, in contrast to the other D vitamins, it has a higher bioavailability, i.e. it can be absorbed more easily by the body and therefore has a better effect. When buying vitamin D supplements, you should therefore make sure that you choose vitamin D3 supplements.
How does a vitamin D deficiency manifest itself?
Factors that support a vitamin D deficiency are, for example, climatic conditions. This means that unfavorable weather conditions and thus low UV-B radiation can be the reason for reduced absorption of the vitamin - even in the summer months. In addition, the altitude, the daily sunshine duration, the ozone content in the air and the air pollution also play a role.
But the absorption of vitamin D depends not only on the outside world, but also on the body's own factors. These include, for example, age, skin color, weight and lifestyle. Especially under the current circumstances, in which people leave their homes as little as possible, a vitamin D deficiency can quickly occur because the body gets less sunlight than under normal conditions. This also means that the time you spend indoors or your leisure activities have an impact on the vitamin D levels in your body.
Vitamin D plays an important role in bone health - so a deficiency can lead to decalcification of the bones (although this is more likely to happen in severe cases). Other symptoms of a deficiency include a decrease in bone density, bone pain and disturbances in the calcium and phosphate metabolism. In addition, low vitamin D levels can lead to poorly healing bone fractures, respiratory infections, depression and mood swings.
In general, when measuring the vitamin D level, it should be noted that it is subject to strong seasonal fluctuations. So if you have your vitamin D level measured once and a low value is measured, it does not necessarily mean that you suffer from a long-term vitamin D deficiency.
How much vitamin D does the body need?
Among other things, the vitamin D saturation in the blood is highly location-dependent. The American physician and author Dr. In his bestseller “How not to die”, Michael Greger writes about foods that keep the body healthy and prevent diseases. Here he recommends vitamin D supplementation for people who live in a latitude over 50 (e.g. Moscow, London and Berlin). This is because the "vitamin D winter" here can last up to six months of the year and the natural absorption of the vitamin from the sun is therefore too low.
The NRV - Nutrients Reference Value - for vitamin D in the body is 5 micrograms for daily intake. The NRV is a guideline for the recommended daily intake of nutrients.
The UK government, meanwhile, advises taking a daily vitamin D supplement of 10 micrograms between October and early March to ensure healthy levels of vitamin D in the body. For some subgroups, especially older people, this recommendation even applies all year round.
Our Level Up AddOn contains 5 micrograms of vitamin D3. So you have consumed 100% of the NRV with the daily intake. The Dailybacs contain an additional 0.75 micrograms of vitamin D3, which corresponds to another 15% of the NRV. The Dailybacs + Level Up AddOn are therefore 5.75 micrograms a day and 115% of the NRV - so you are taking them slightly below the British government's recommendation. So you can easily add another vitamin D3 dietary supplement to your intake or take more vitamin D from foods such as fatty sea fish, mushrooms or eggs, but the Dailybacs + AddOns are already a very good dietary supplement.
Vitamin D and the immune system
As already explained, vitamin D not only has an impact on bone health, but also on metabolism and the immune system. This can lead to a vitamin D deficiency, especially in times with little sun and also in times of exit restrictions. This in turn can have consequences for our immune system and impair the performance of the immune system. Older people are particularly affected by this, as the ability of the skin to produce vitamin D decreases with age.
In the study "the vitamin D receptor and T cell function", a Danish research team explains the interactions between vitamin D and the human immune system. They come to the conclusion that the vitamin activates important cells of the immune system - so-called killer cells. As the name suggests, these have the task of fighting pathogens and toxins in the organism.
In conclusion, this means: if there is too little vitamin D in the body, the killer cells in the body are less activated and the immune system is therefore less efficient. A lower defense capacity of the body, in turn, means that pathogens can penetrate the organism more easily and you become ill more quickly.
- Dr. Michael Greger: How not to die - Discover foods that extend your life and are proven to prevent and cure diseases, 2016, Unimedica
- Martin Kongsbak, Trine B. Levring, Carsten Geisler, & Marina Rode von Essen. The Vitamin D Receptor and T Cell Function. Front Immunol. 2013; 4:148. Published online 2013 Jun 18. doi: 10.3389/fimmu.201300148