The importance of vitamin D for your health

A balanced and varied diet is rightly considered the best basis for a long, healthy and productive life. However, not all vital nutrients can be easily obtained in sufficient quantities through food. This is especially true for the supply of vitamin D - probably the most prominent vitamin deficiency!

Why do many people suffer from vitamin D deficiency?

While the need for many vitamins can be met through diet, the main absorption of vitamin D occurs through exposure to sunlight on the skin. For this reason, vitamin D is also known as the sunshine vitamin.

A poor supply of vitamin D can have very different consequences. And unfortunately, undersupply is not that rare, as studies show that more than half of all Europeans have a vitamin D status that is too low. Around 18% even suffer from an acute vitamin D deficiency (1).

Causes of Vitamin D Deficiency

Long periods spent indoors, effective sun protection and, last but not least, the lack of or weak sun during the long winter months mean that vitamin D has become a vitamin deficiency in the European population. Even in summer, many people find it difficult to get enough vitamin D, partly for professional reasons or the frequent use of sunscreen.

Small vitamin, big impact! Why is vitamin D so important?

A lot has happened in research on vitamin D in the last ten years, which is why a deficiency is problematic even if it is not as obvious as in the case of rickets. Scientists now know that vitamin D plays a role in basically everything.

Some metabolic processes have to take place before the biologically active form of the vitamin, known as calcitriol, is formed in the kidneys and released into the blood. It was previously thought that the calcitriol in the blood was the key biologically active metabolite that mediates all effects. However, according to the latest findings, this is not the case; the calcitriol in the blood probably only regulates calcium-bone metabolism.

Vitamin D and its versatile functions in the body

For a long time, it was assumed that if you have enough calcitriol in your blood, you cannot suffer from vitamin D deficiency. But then, a few years ago, researchers discovered that the body uses vitamin D in a completely different way.

Almost all organs have vitamin D receptors. This has been known for a long time. A precursor of calcitriol, which is also found in the blood but is not yet biologically active, binds to these receptors. The organs then produce calcitriol themselves from this precursor, which is used for countless other processes in the body.

This form of vitamin D regulates insulin secretion, inhibits tumor growth, promotes the formation of red blood cells and the survival and activity of macrophages, which are important for the immune system. However, the calcitriol produced by the various organs does not return to the blood, which is why this synthesis pathway remained hidden from researchers for a long time.

Vitamin D for immune function and health

For our vitamin D requirements, this means that we need much more than the limit previously considered sufficient. “It is now assumed that we need around 20 to 30 nanograms of vitamin D per milliliter of blood.” That is around twice to three times as much as was previously assumed.

Vitamin D plays a central role in human health and performance. Above all, because vitamin D has been proven to support immune function. Without a functioning and, above all, efficient immune system, the human organism would be defenseless against pathogens such as bacteria and viruses.

It is therefore not surprising that science attests that vitamin D plays an important role in the fight against the novel lung disease Covid-19, which is caused by the pathogen SARS-CoV-2 (coronavirus). (2)

Symptoms of vitamin D deficiency and its effects

Vitamin D deficiencies often not only result in an increased susceptibility to infections, but can also cause symptoms such as fatigue or even depression. Vitamin D also plays an important role in bone health and muscle function.

How can an adequate supply of vitamin D be achieved?

While vitamin D can be easily absorbed by spending time outdoors in the summer, stores are drastically depleted in the autumn and winter months. Spending time outdoors can do little to change this, as the sun has lost too much of its strength.

In this case, it is advisable to ensure a vitamin D supply through dietary supplements. Interesting in this context: The latest studies confirm that orally ingested vitamin D can increase vitamin D levels more than is possible through exposure to sunlight. (3)

Anyone who decides to take a targeted vitamin D3 supplement should always keep an eye on their vitamin K2 supply. The reason for this is that both vitamins work synergistically.

Vitamin D influences calcium absorption, which increases the calcium concentration in the blood, which in turn is used

(1)   Kevin D Cashman,* Kirsten G Dowling, Zuzana Škrabáková, Marcela Gonzalez-Gross, Jara Valtueña, Stefaan De Henauw, Luis Moreno, Camilla T Damsgaard, Kim F Michaelsen, Christian Mølgaard, Rolf Jorde, Guri Grimnes, George Moschonis, Christina Mavrogianni, Yannis Manios, Michael Thamm, Gert BM Mensink, Martina Rabenberg, Markus A Busch, Lorna Cox, Sarah Meadows, Gail Goldberg, Ann Prentice, Jacqueline M Dekker, Giel Nijpels, Stefan Pilz, Karin M Swart, Natasja M van Schoor, Paul Lips, Gudny Eiriksdottir, Vilmundur Gudnason, Mary Frances Cotch, Seppo Koskinen, Christel Lamberg-Allardt, Ramon A Durazo-Arvizu, Christopher T Sempos, and Mairead Kiely. “Vitamin D deficiency in Europe: pandemic?”, at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5527850/, last accessed on February 18, 2021

(2)   Marta Entrenas Castillo,a Luis Manuel Entrenas Costa,a,* José Manuel Vaquero Barrios,a Juan Francisco Alcalá Díaz,b José López Miranda,b Roger Bouillon,c and José Manuel Quesada Gomezd, NCBI, "Effect of calcifediol treatment and best available therapy versus best available therapy on intensive care unit admission and mortality among patients hospitalized for COVID-19: A pilot randomized clinical study", at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7456194/, last accessed on February 18, 2021

(3)   Hee-Kyung Joh, Seung-Sik Hwang, BeLong Cho, Chun Soo Lim, Sung-Eun Jung, NCBI, “Effect of sun exposure versus oral vitamin D supplementation on serum 25-hydroxyvitamin D concentrations in young adults: A randomized clinical trial,” at: https://pubmed.ncbi.nlm.nih.gov/30987813/, last accessed February 18, 2021