Vitamin D3: the properties of the most essential vitamin

Is the natural sun enough?

Ironically, although France enjoys a generous amount of sun, modern lifestyles have led to interior habits and a reduction in sun exposure. Long hours of interior work, the omnipresence of sunscreen and even concern about skin aging have caused a significant reduction in the time that is passed to the sun, which directly affects the cutaneous synthesis of vitamin D.

At the same time, vitamin D intake through food can sometimes be insufficient to meet the recommended daily needs, especially since the amount of vitamin D of these sources can vary considerably (see the picture).

To confirm it, an important national study has recently demonstrated that

• 80% of people have a lack of vitamin D (levels below 0.30 ng/l)
• 42.5% have a serious to severe lack (levels <0.20 ng/l)

After conversion, this corresponds to less than 75 and 50 IU per day.

In such situations, vitamin D supplements administration is especially useful. In addition, certain populations, such as vegans, may have difficulty reaching recommended levels, since plant sources of vitamin D are limited.

Vitamin D: A first historical observation

When we observe the history of vitamins, minerals and other components used today in human health, we often realize that its history began long before laboratory research. In fact, many civilizations had adopted and empirically adopted certain behaviors to mitigate the effects of the lack of vitamin D, long before there was a tangible knowledge of this substance.

As expected, it was through the sun and its rays as man praised for the first time the positive effects of vitamin D. It was during one of his visits to Egypt when Greek Herodotus referred to its existence. During his scale in an old theater of clashes between Persians and Egyptians, he wondered why Persian skulls were so fragile compared to the Egyptians. The Egyptians explained to Herodotus that this difference was because they exposed their naked heads to sunlight from childhood. Instead, the Persians, when covering their heads with turbans, deprived themselves of this direct exposure to the sun, which weakened their skulls.

Key dates in the modern history of vitamin D3

The history The modern discovery of vitamin D is very rich and dates back to the beginning of the last century. Many researchers have contributed to their discovery and understanding their mechanisms. To throw some light on the subject, we review some of the key dates and periods that have surrounded the advances in the human understanding of this molecule.

• 1919: Sir Edward Mellanby discovers the possible cause of rickets, linked to a reduced intake of the anti -rags factor (later identified as vitamin A);
• 1920 decade: Frederick G. Hopkins contributes to the knowledge of essential dietary factors, reinforcing nutritional understanding;
• 1920-30: Harriette Chick, influenced by her British colleagues, highlights the crucial importance of vitamin D in the prevention of rickets, without distinguishing between vitamin D2 and D3;
• 1936: Adolf Windaus and Walter Norman Haworth identify the chemical structure of vitamin D3, establishing the distinction between vitamin D2 (Ergocalciferol) and vitamin D3 (collectorciferol);
• 1970-1980: Molecular discovery of vitamin D, which reveals the structure of vitamins D2 and D3, deepening our understanding of their physiological role;
• 1980-1990 years: Studies deepen the specific effects on the health of vitamin D2 and vitamin D3, in particular its effectiveness in the treatment of rickets and its implications for bone health;
• 2010-2020 years: Modern studies highlight the importance of vitamin D3 compared to vitamin D2, especially in the maintenance of blood levels and their health benefits.