Vitamin D and Immune System Health

Category_Immune System Support flu flu season immune system immune system health immunity sunshine virus vitamin D vitamin D3 Vitamin K2 with D3

Vitamin D and Immune System HealthWe've all heard Vitamin D referred to as the "sunshine vitamin," but it is actually a precursor to a hormone synthesized by the body when activated by the sun's rays. Only a small amount of Vitamin D comes from the food we eat.1 Many people in the northern hemisphere as well as people who work inside all day in the southern hemisphere are deficient in Vitamin D. Elderly males who live in the tropics have even been found to have low Vitamin D levels.2 Vitamin D insufficiency has become a global issue,3 and affects people of all ages and ethnicities—primarily in developed countries.4 Vitamin D is crucial to immune system health. Besides its well-known roll in bone health, Vitamin D acts as a sort of signal and modulator within the immune system, as well as playing a key role in the antimicrobial response.5 Vitamin D was used, albeit unknowingly, for the treatment of tuberculosis in sanatoriums wherein people would be made to get a certain amount of sunlight every day.6 Vitamin D has also been shown to increase the antiviral activity in bronchial cells in vitro.7 Low Vitamin D levels have been linked to major chronic diseases and strongly associated with higher susceptibility to several autoimmune diseases.8

Flu Season and Vitamin D

Because the flu is far more prevalent in the winter months, it led British doctor, R. Edgar Hope-Simpson, in 1981 to question whether the “flu season” was related to low Vitamin D levels in the population. 20 years on, his “seasonal stimulus” hypothesis is becoming far more interesting to researchers and is being studied as a distinct possibility.9 Vitamin D levels do indeed fluctuate, and are lower in the winter months. People with low Vitamin D levels are usually the ones who come down with colds, coughs and upper respiratory infections more often.10,11

Vitamin D and COVID-19

Vitamin D (as well as zinc) has come to the fore as one of the main immune-boosting supplements in the fight against COVID-19. Vitamin D also, "appears to play a role in COVID-19 mortality rates." 12

Sources of Vitamin D

  1. Sunshine (15-20 minutes a day on bare arms and legs)
  2. Fatty varieties of fish (salmon, mackerel, tuna and sardines)
  3. Dietary Supplementation
For many people, getting 15 – 20 minutes per day of sunshine on bare arms and legs throughout the year is an impossibility, not to mention the fact that many people are highly susceptible to skin cancer. For vegans and people who just can't stand to eat fish, item number 2 above isn't an option either.

Vitamin K2 with D3

Vitamin K2 with D3 Dietary Supplement Doctor Emi's Vitamin K2 with D3 differs from most Vitamin D supplements in that it also contains K2 in the form of menaquinone-7 which makes the Vitamin D3 absorb into the system properly; and the D3 is in the form of cholecalciferol – the identical form in which Vitamin D is derived in the body from cholesterol and synthesized by sunlight on the skin. Doctor Emi's Vitamin K2 with D3 is:
  • Non-GMO
  • Soy-Free
  • Gluten-Free
  • Made in the USA
  • Manufactured in a GMP Compliant Facility
Please discuss this, or any dietary supplement you take or wish to take, with your physician. Dietary supplements can react with prescription medications as well as with one another. The Doctor Emi Team
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1. Hormone Health Network."Vitamin D | Endocrine Society.", Endocrine Society, 20 March 2020,
2. Cabral MA, Borges CN, Maia JM, Aires CA, Bandeira F. Prevalence of vitamin D deficiency during the summer and its relationship with sun exposure and skin phototype in elderly men living in the tropics. Clin Interv Aging. 2013;8:1347–1351. doi:10.2147/CIA.S47058
3. Vitamin D. The Nutrition Source. Harvard T.H. Chan.
4. Hassan-Smith ZK1,2,3, Hewison M2,3, Gittoes NJ1,2,3. Effect of vitamin D deficiency in developed countries. Br Med Bull. 2017 Jun 1;122(1):79-89. doi: 10.1093/bmb/ldx005.
5. Hewison M1. Vitamin D and immune function: an overview. Proc Nutr Soc. 2012 Feb;71(1):50-61. doi: 10.1017/S0029665111001650. Epub 2011 Aug 18.
6. Aranow C. Vitamin D and the immune system. J Investig Med. 2011;59(6):881–886. doi:10.2310/JIM.0b013e31821b8755.
7. Aurica G.TelcianaMihnea T.ZdrengheabMichael R.EdwardsaVasileLaza-StancaaPatrickMalliaacSebastian L.Johnstonac1Luminita A.Stanciuab1. Vitamin D increases the antiviral activity of bronchial epithelial cells in vitro. Received 4 July 2016, Revised 1 November 2016, Accepted 4 November 2016, Available online 10 November 2016. Antiviral Research. Volume 137, January 2017, Pages 93-101.
8. University of Edinburgh. (2019, April 17). Vitamin D study sheds light on immune system effects. ScienceDaily. Retrieved March 20, 2020 from
9. Cannell JJ, Vieth R, Umhau JC, et al. Epidemic influenza and vitamin D. Epidemiol Infect. 2006;134(6):1129–1140. doi:10.1017/S0950268806007175.
10. Vitamin D. The Nutrition Source. Harvard T.H. Chan.
11. Holick MF1. Vitamin D deficiency. N Engl J Med. 2007 Jul 19;357(3):266-81. PMID: 17634462 DOI: 10.1056/NEJMra070553.
12. Backman V. Vitamin D appears to play role in COVID-19 mortality rates. May 07, 2020. News.Northwestern.Edu

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