In many areas of the country, due to abundant rainfall, this year has been extraordinarily fertile. Just as raindrops made plants grow and trees bear fruit, so too does each "drop" of vitamin D reach the cells of the human body, bringing countless benefits: it strengthens some to fight against microbes, helps others absorb calcium, while keeping a balanced rhythm of functioning for others.
For a long time, Vitamin D was renowned for optimal calcium absorption and strong bones. Now it is appreciated for multiple other roles, all of which are very important. We will learn more about them in the following.
What is Vitamin D?
Vitamin D is an essential micronutrient. Many doctors and researchers consider it a hormone, activating over 2,500 genes, with receptors for it existing in almost all cells of the human body. It is formed in the skin from cholesterol (this explains why it is fat-soluble), under the action of ultraviolet radiation, which we find, especially, between 11 AM and 2 PM. Be careful, only 10-15 minutes of exposure are needed to synthesize a sufficient amount! From the skin, cholecalciferol or vitamin D3 (also available in supplements) is transported to the liver, where it transforms into calcidiol, after which it reaches the kidneys, where it is converted to its active form, calcitriol, which is sent to the body's cells to perform its specific functions.
The body can also obtain it from food sources:
- vitamin D3 of animal origin (herring, salmon, mackerel, sardines, cod liver, beef or chicken liver, eggs, etc.);
- vitamin D2 of plant origin (mushrooms and yeasts).
Vitamin D3 is considered to have better absorption and stability than vitamin D2.
When discussing supplements, the most suitable ones are those from natural sources (consult the label, where the origin of Vitamin D extraction is specified) and with an oily composition.
What does Vitamin D do in the human body?
- it is a modulator of the immune system: it strengthens leukocytes in their fight against microbes, protecting against infections and colds, and at the same time tempers a potential exaggerated immune reaction, preventing "cytokine storm", allergies, and autoimmune diseases.
- it reduces the incidence of chronic conditions, such as diabetes, because an optimal level of vitamin D diminishes insulin resistance.
- it protects the cardiovascular system: it reduces generalized inflammation and, thus, atherosclerosis, preventing myocardial infarction; it regulates renin, involved in the onset of high blood pressure, supports proper heart contraction, and maintains the elasticity of blood vessels.
- it prevents the onset of neurodegenerative diseases (multiple sclerosis, Alzheimer's, Parkinson's). Through receptors existing in the central nervous system, vitamin D reduces inflammation, helps remove amyloid plaques, maintains an optimal concentration of calcium in nerve cells, preventing their destruction.
- it stimulates the growth and development of hair follicles and keratin.
- it combats depression and improves mood by amplifying the activity of GABA, acetylcholine, and dopamine, and by increasing the number of receptors for these substances.
- it improves sleep quality, but the most effective vitamin D is that obtained through sun exposure, because this naturally increases serotonin and melatonin levels.
- it regulates certain hormones: it inhibits excessive parathyroid hormone production, aids in adequate secretion of insulin, estrogen, and testosterone.
- it increases calcium absorption in the intestine by over twenty times. Be careful, for its deposition in bones, an optimal level of vitamin K2 and vitamin C, otherwise it can be deposited in the kidneys or blood vessels! Therefore, supplementation with these vitamins is also necessary.
- can facilitate the weight loss process. Studies have shown that a minimum level of 32 ng/ml helped with more efficient weight loss. The mechanisms are not fully understood, but it is assumed that it regulates fat metabolism, increases insulin sensitivity, and inhibits excessive appetite.
- lowers overall mortality, slows down aging and prolongs life, by reducing the rate of telomere shortening, decreasing oxidative stress and chronic inflammation. However, in case of excessively high vitamin D levels, the aging process accelerates.
Sometimes, vitamin D "drops" are insufficient for all these functions, and the body will prioritize the use of vitamin D only for certain organs and situations. How could we recognize a vitamin D "drought"? We will find out in the next article...
(to be continued)
Dr. Daniela Ilioiu
Photos by Kindel Media, Eddie O., Nataliya Vaitkevich, Rainer Eck / pexels.com