I am aware of two reports on the increase of rhinosinusitis in persons who had Vit. D3 deficiency.

One study indicated decrease of Vit D3 may decrease T reg cells in sinus cavity. Also it increased impact on mucosa by IFN-gamma, IL-6, IL-10, TNF-alpha, but not IL-17, all led to development of sinusitis (Plos One, 2017, Oct. 18).

The other study showed Vit D3 deficiency could be associated with increase of nasal polyps in the sinus cavity. Authors believe Vit D3 deficiency increased substantial microbial colonization on mucosa that led to sinusits (Am J Rhinol Allergy, 2017, November).

Shih-Wen Huang, MD

University of Florida

A recent systematic review and meta-analysis which was conducted to investigate the relationship between vitamin D levels and allergic rhinitis found that prior vitamin D levels were not related to developing allergic rhinitis, but lower vitamin D levels were associated with a higher allergic rhinitis prevalence only in children. Also, the evidence supporting vitamin D supplementation for allergic rhinitis prevention is insufficient. The authors recommended physicians should consider evaluating patients for vitamin D deficiency during allergic rhinitis management, especially in children

I would think rhinosinusitis, the topic of question, is different from allergic rhinitis. The rhinosinusitis used to be called either acute or chronic sinusitis. Allergic rhinitis could be either seasonal or perennial rhinitis.

Just to make it clear the latter does not involve inflammation in the sinus cavities.

Shih-Wen Huang, MD

Vitamin d3 is necessary for good immune system

Vitamin D has numerous effects on cells within the immune system.

1.It inhibits B cell proliferation and blocks B cell differentiation and immunoglobulin secretion.

2.Vitamin D additionally suppresses T cell proliferation and results in a shift from a Th1 to a Th2 phenotype.

3.It affects T cell maturation with a skewing away from the inflammatory Th17 phenotype and facilitates the induction of T regulatory cells. These effects result in decreased production of inflammatory cytokines (IL-17, IL-21) with increased production of anti-inflammatory cytokines such as IL-10.

4.Vitamin D also has effects on monocytes and dendritic cells (DCs). It inhibits monocyte production of inflammatory cytokines such as IL-1, IL-6, IL-8, IL-12 and TNFα.

5. It additionally inhibits DC differentiation and maturation with preservation of an immature phenotype as evidenced by a decreased expression of MHC class II molecules, co-stimulatory molecules and IL12.

Thanks all for lovely discussion here.

Since vitamin D3 has intra nuclear receptor. Role of vitamin D3 supplimentation in the fludity of plasma membrane and mucocillary clearance in sinuses.