Vitamin D is known as the "vitamin of the Sun". Its initial and most effective source is exposure to sunlight; however, its journey is a very complicated series of chemical changes that happen inside our bodies to transform sunlight into a vital vitamin that performs pivotal roles in our health.
The journey begins when the skin is exposed to ultra violet rays through sunlight. From this moment, a chemical compound found in the skin cells known as Dehydrocholesterol-7 is converted into vitamin D3 (D3-Cholecalciferol); this change is the first essential step in the vitamin production inside the body.
The newly formed D3 vitamin in the skin is then moved to the liver where it undergoes another chemical transformation by a specific enzyme, turning it into a compound known as hydroxyvitamin D-25 or Calcidiol. Calcidiol is the main form of vitamin D stored in the body and is also the marker that is used in the medical tests to measure vitamin D levels in the blood.
The last step in this chemical chain takes place in the kidneys. Inside the kidney, the Calcidiol is transformed into the biologically active form of vitamin D, which is called Dihydroxyvitamin-1.25D or Calcitriol; the form that performs the vitamin's vital functions in the body.
What is the Importance of Vitamin D?
The importance of vitamin D lurks in its pivotal role in regulating calcium and phosphate levels in the blood; two essential minerals for healthy bones and teeth. It enhances the absorption of calcium from the intestines and helps in its deposition in the bones, contributing to building of strong, healthy bones and protecting against diseases such as rickets and osteoporosis.
Recent researches show that vitamin D role is not restricted to bone health and immunity, but also in many other functions in the body, such as regulating cell growth, reducing inflammation, supporting cardiovascular health, and even preventing certain types of cancer. Moreover, some researches suggest that it has an effect on mood and mental health, as its deficiency is linked to an increased risk of depression. These multiple roles affirm the importance of maintaining adequate levels of this vitamin to ensure overall body health and prevent chronic diseases.
Vitamin D Deficiency: A Global Issue
Despite its extreme importance, vitamin D deficiency is a common global health problem, because achieving optimal vitamin D levels can be challenging for so many people, especially in the regions with limited sunlight exposure. Furthermore, the modern life style involves spending most of the time in closed areas and wearing sunscreens, in addition to the seasonal changes in the intensity of the sunlight; all together limit adequate exposure to sunlight.
Therefore, obtaining vitamin D from foods; such as fatty fish like salmon, mackerel, and sardines, and foods fortified with vitamin D, such as milk and some breakfast cereals, is essential for maintaining its optimal levels in the body. In some cases, doctors may recommend nutritional supplements. However, it is important to consult a doctor before starting to take any supplement to decide the appropriate intake and to avoid any side effects.
Our deep understanding of vitamin D's journey from its natural source to the complex chemical reactions inside our bodies enhances our understanding of its importance and motivates us to adopt healthy habits that ensure that we get the most out of this unique nutrient.
References
pmc.ncbi.nlm.nih.gov
stacks.cdc.gov