Loss of smell related to low Vitamin D or Zinc

Olfactory impairment if < 10 ng of Vitamin D - June 2026

Serum vitamin D levels and olfactory function in adults: a cross-sectional study with dose-response and ROC analysis

Eur Arch Otorhinolaryngol 2026 Jun 1. doi: 10.1007/s00405-026-10327-4. PDF behind paywall

Esin Baran 1, Burak Numan Ugurlu 2, Eda Simsek 3

Purpose: The purpose of this study was to examine the relationship between serum 25(OH)D levels and olfactory function in adults, given the emerging recognition of vitamin D as a neurosteroid with potential influence on sensory pathways. Specifically, the study aimed to determine whether vitamin D status is associated with olfactory threshold and identification performance, to explore the presence of a biologically plausible dose-response pattern, and to assess the predictive value of serum vitamin D levels for olfactory dysfunction.

Methods: In this cross-sectional study, 161 adults were enrolled, including 98 with vitamin D deficiency and 63 with sufficient levels. Serum 25(OH)D was measured by HPLC and categorized into four groups (< 10, 10-20, 20-30, ≥ 30 ng/mL). Olfactory threshold and identification were assessed using the Sniffin' Sticks rapid screening kit. Group comparisons, subgroup analyses, correlation tests, multiple linear regression, and ROC analysis (threshold < 7) were performed.

Results: Vitamin D-deficient participants had significantly lower threshold and identification scores than controls (p = 0.008 and p < 0.001). Both scores increased stepwise across vitamin D subgroups (p < 0.001). Serum 25(OH)D correlated positively with threshold (r = 0.302) and identification (r = 0.432) (both p < 0.001); in the deficiency group, the correlation persisted only for threshold. Vitamin D was an independent predictor of identification (β = 0.041; p < 0.001). ROC analysis indicated that severe vitamin D deficiency (cutoff ≈ 10 ng/mL) was strongly associated with threshold-level olfactory impairment (AUC 0.636; specificity 95%).

Conclusion: Serum vitamin D level is associated with olfactory function, particularly odor identification, and shows a biologically plausible dose-response pattern. Vitamin D appears to be a specific risk indicator rather than a standalone diagnostic marker for olfactory dysfunction.

2X more likely to have taste impairment if aged 70–80 if Vit D 20-30 ng - April 2020

Age-related Smell and Taste Impairments and Vitamin D Associations in the U.S. Adults National Health and Nutrition Examination Survey

Galya Bigman

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A possible correlation between vitamin D deficiency and loss of smell: 2 case reports – 2011

2 people reported increased ability to smell after increasing vitamin D levels

With 10,000 IU of vitamin D daily her ability to smell started to return after a few months

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VitaminDWiki Observations

Loss of taste and smell sensitivity after chemotherapy, which is associated with low Vitamin D
Loss of smell associated with obesity – which is associated with low Vitamin D
Loss of smell is an early indication of both Parkinson’s and Alzheimer’s diseases, which are associated with low Vitamin D
Loss of smell and taste is associated with Multiple Sclerosis, which is associated with low Vitamin D

Loss of smell related to low Vitamin D or Zinc

Olfactory impairment if < 10 ng of Vitamin D - June 2026

2X more likely to have taste impairment if aged 70–80 if Vit D 20-30 ng - April 2020

A possible correlation between vitamin D deficiency and loss of smell: 2 case reports – 2011

VitaminDWiki Observations

See also VitaminDWiki

See also web

See also: smell and Zinc on the web