Vitamin D and Immune Function

A short and recent literature review of Vitamin D and Immune Function.

If you’re at all involved or invested / interested in your health, you’ve probably heard that Vitamin D is pretty important in the overall process. I’ve written before about supplementation (of Vitamin D) compared to the sun and postulated some reasons why the former is, by far, inferior. At any rate, the following came across my feed this week:

Vitamin D and its therapeutic relevance in pulmonary diseases

Studies have displayed strong inter-relations with vitamin D deficiency and progression of lung disorders; however, the underlying mechanism is still unknown. Vitamin D has emerged to possess inhibiting effects on pulmonary inflammation while exaggerating innate immune defenses…

~ The Journal of Nutritional Biochemistry

Part of the abstract reads, “Almost all of the pulmonary diseases including acute lung injury, cystic fibrosis, asthma, COPD, Pneumonia and Tuberculosis, all are inflammatory in nature. “ Perhaps, too, this might be relevant to a certain other respiratory disease that’s been making headlines for the past year(!).

“Vitamin D insufficiency as a potential culprit in critical COVID-19 patients” doesn’t seem like the sort of thing CNN (or FOX for that matter) is going to broadcast. Yet, this meta analysis from February 2021 found that “Patients with poor prognosis had significantly lower serum levels of Vitamin D compared with those with good prognosis”( 2). The article, from The Journal of Medical Vironlogy (seems reputable!), concluded that “Serum vitamin D levels could be implicated in the COVID-19 prognosis. Diagnosis of vitamin D deficiency could be a helpful adjunct in assessing patients’ potential of developing severe COVID-19. Appropriate preventative and/or therapeutic intervention may improve COVID-19 outcomes.”.

Similarly, Reviews in Medical Virology published an article in 2017 worte “ Vitamin D, in addition to its classical functions in bone homeostasis, has a modulatory and regulatory role in multiple processes, including host defense, inflammation, immunity, and epithelial repair. Patients with respiratory disease are frequently deficient in vitamin D, implying that supplementation might provide significant benefit to these patients.” ( 3) — though they prefer supplementation as treatment.

Another meta-analysis from 2013 wrote that; “In humans, vitamin D is mainly synthesized in the skin after exposure to UVB whereas only a minor part is derived from dietary sources.”( 4) “Dietary sources” also includes supplements if you’re wondering.

They continued:

In recent decades, vitamin D research has confirmed important interactions between vitamin D and cells from the innate as well as from the adaptive immune system… This process seems to be essential for normal immune function and therefore impaired or insufficient vitamin D levels may lead to dysregulation of immune responses… However, taking all current evidence together, vitamin D emerges as a promising and relatively safe nutrient for new strategies in the prevention and adjunctive treatment of diseases caused by impaired immune-homeostasis.

In fact, the immune function of Vitamin D is so strong that it has been implied in the treatment of tuberculosis and Type 1 diabetes ( 5)!

Coming back to the future, in January 2021 the British Medical Journal of Global Health published “Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis.” They concluded that “Vitamin D supplementation reduced the risk of (Acute respiratory tract infections) and shortened the duration of symptoms (-9%).” They concluded that “Our synthesis of global evidence from randomised controlled trials indicates that micronutrient supplements including zinc, vitamins C and D, and multiple micronutrient supplements may be modestly effective in preventing ARIs and improving their clinical course. Further research is warranted to better understand the effectiveness that individual or multiple micronutrients have on SARS-CoV-2 infection and treatment outcomes.”( 6)

Stay radically healthy! Play in the sun!