Stay Healthy All Year with Vitamin D By Tara Tranguch, ND
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itamin D is emerging as a good preventive measure for COVID-19 both to bolster immune response and to dampen the escalating inflammatory response, which can lead to Acute Respiratory Distress Syndrome (ARDS). Vitamin D is one of four fat-soluble vitamins (the others being A, E and K) and it serves as a hormone precursor. Precursors are metabolically inactive. It undergoes two reactions in the body to become active and our kidney makes 1,25OH-D3, which is the biologically active form in the body that functions as a steroid hormone. How Active Vitamin D is Made in The Body 1. UVB light from the sun is absorbed by the skin and converts 7-dehydrocholesterol to Vitamin D3, called cholecalciferol. If you take a D3 supplement, this is the form you are taking - cholecalciferol. 2. Vitamin D3 then travels to the liver where it undergoes a hydroxylation reaction and is converted into 25OHD3, also known as calcifediol. If you test your Vitamin D levels, they test blood levels of 25OH-D3. This is the form used for testing because it has the longest half-life in the body.
3. 25OH-D3 then travels to the kidney where it is hydroxylated again to form either: 1) active 1,25OH-D3, also known as calcitriol, which increases blood calcium levels, or 2) active 24,25OH-D3, which decreases blood calcium levels. Whether 25OH-D3 converts to 1,25OH-D3 or 24,25OH-D3 depends on the parathyroid gland, parathyroid hormone and serum calcium levels. Once active Vitamin D3 is in the blood, it can only start to work after it binds to various proteins such as VDR and GC. Once it binds to the protein, a cascade of action is kicked off that acts on: • Calcium and phosphorous levels • Bone mineralization and remodeling • Dental health • Innate and adaptive immune response modulation • Inflammation • Endocrine, glucose and cardiovascular systems. Binding to VDR and GC is necessary for Vitamin D to do anything in your body. It’s not solely your blood levels of Vitamin D3 that determine if you have enough Vitamin D3; your Vitamin D genetic pathways are also significant.
Genes Involved with Vitamin D Activity 1. VDR: Gene for the Vitamin D receptor. It binds with Vitamin D and is involved in regulating inflammation, insulinlike growth factor signaling, estrogenrelated pathways, calcium absorption in the stomach and intestines, and bone strength. Gene variants such as having the A allele in VDR has been associated with reduced bone mineral density and osteoporosis. The VDR is also expressed on immune cells such as B cells, T cells and antigenpresenting cells, which means all of these cells are capable of synthesizing the active Vitamin D metabolite. This explains the direct effect Vitamin D has on our immune system. Multiple studies have been done to assess the positive effect of Vitamin D on patients with COVID-19. One study showed that administration of oral 1,25OH-D3 to COVID positive patients resulted in less severity of the disease including reduced rate of ICU admission and reduced mortality. Research found that when Vitamin D binds to VDR, it “may generate beneficial effects on ARDS by decreasing the cytokine/chemokine storm, regulating the renin-angiotensin system, modulating neutrophil activity and by maintaining the integrity of pulmonary www.NaturalNutmeg.com
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