Does vitamin D help with the sense of smell?

October 18, 2025 •

4 min read

According to research published in the journal Nutrients, individuals with low serum vitamin D levels were found to have a significantly higher prevalence of age-related smell impairment. This finding has sparked considerable interest in how vitamin D might influence the crucial sensory function of our nose.

Quick Summary

Studies suggest a correlation between lower vitamin D levels and impaired olfactory function, with evidence from case reports showing improved smell after supplementation.

Key Points

Correlation: Vitamin D deficiency is statistically linked to a higher risk of smell impairment, particularly in older adults.
Mechanism: Vitamin D receptors are present in the brain's olfactory network, and vitamin D acts as a neurosteroid with neuroprotective effects.
Supplementation: Some case studies have reported significant improvements in smell after patients with diagnosed deficiency received vitamin D supplements.
Inflammation: The anti-inflammatory properties of vitamin D may help mitigate inflammation in the nasal and sinus passages that can obstruct smell.
Other Factors: Olfactory dysfunction can be caused by numerous factors, so it is essential to have an underlying deficiency properly diagnosed by a doctor.
Enhancement: Combining proper vitamin D intake with smell training exercises may be an effective strategy for restoring or enhancing olfactory function.

The Relationship Between Vitamin D and Olfaction

For many years, vitamin D was primarily known for its role in maintaining bone health through calcium regulation. However, in recent decades, mounting evidence has revealed its extensive function throughout the body, including in the nervous system. The discovery of vitamin D receptors (VDRs) and the necessary enzymes for its activation in the brain, including the olfactory network, indicates a more direct link to neurological function, which includes our sense of smell.

The Role of Vitamin D in the Olfactory System

Research has explored several potential mechanisms by which vitamin D deficiency can lead to a reduced sense of smell, or anosmia/hyposmia. These mechanisms highlight the vitamin's multifaceted role in maintaining neurological health and proper cellular function.

Neuroprotective Effects: Vitamin D has been shown to have neuroprotective effects, promoting neuronal growth and protecting neurons from damage caused by oxidative stress and inflammation. Within the olfactory system, these protective actions are critical for the health and function of the delicate olfactory receptor neurons and the olfactory bulb in the brain.
Immunomodulatory Effects: Vitamin D's influence on the immune system may indirectly help the sense of smell. It can reduce inflammation, which is a key factor in conditions like chronic rhinitis and sinus infections that can lead to nasal obstruction and subsequent smell loss. By modulating inflammation, vitamin D may help maintain a clear nasal passage for odorants to be detected.
Gene Expression and Neuronal Signaling: Vitamin D, via the vitamin D receptor (VDR), acts as a hormone that can regulate the expression of various genes. In the olfactory system, this can influence the synthesis of important neurotrophic factors and the functioning of neurotransmitter pathways crucial for processing olfactory information. Animal studies have shown that VDR knockdown in the olfactory bulb impairs smell function.

Scientific Evidence on Vitamin D and Smell

Several studies have explored the connection between vitamin D levels and olfactory function, yielding notable results:

Cross-sectional studies: A large-scale US study (NHANES 2013–2014) found that adults aged 40–80 with vitamin D deficiency (<20 ng/mL) were 39% more likely to report smell impairment compared to those with sufficient levels (>30 ng/mL).
Interventional studies: Case reports have documented individuals with diminished olfaction and diagnosed vitamin D deficiency who experienced significant improvement in their sense of smell after receiving vitamin D supplementation.
Animal studies: Research on mice has demonstrated that dietary vitamin D levels directly impact olfactory acuity. Deficiency impairs odor discrimination, while supplementation enhances sensitivity.
Systematic reviews: A 2022 systematic review analyzing studies between 2000 and 2022 identified a significant relationship between vitamin D deficiency and smell impairment. The review concluded that as vitamin D supplementation is cost-effective, further large-scale research is warranted.

Factors Influencing the Sense of Smell

Vitamin D is just one piece of a larger puzzle. Many factors, both internal and external, can influence the sense of smell. These can include:

Age-related decline
Head trauma
Upper respiratory infections (e.g., common cold, flu, COVID-19)
Chronic nasal and sinus inflammation
Nasal polyps
Medications
Exposure to environmental toxins
Smoking
Other nutrient deficiencies (like zinc or vitamin B12)

It is important to address all potential causes of olfactory dysfunction, and a medical professional can help determine the root cause through proper testing.

Sources of Vitamin D and Enhancing Your Smell

To ensure adequate vitamin D levels, consider the following sources. The body's primary source is sunlight exposure, which stimulates vitamin D production in the skin. Dietary sources are also important, and many foods are fortified to boost intake.

Natural and Fortified Sources of Vitamin D


Source Category	Example Foods	IU per Serving (Approximate)	Purpose
Fatty Fish	Salmon, Mackerel, Tuna, Sardines	Varies (e.g., 570 IU in 3 oz cooked salmon)	Excellent natural source; incorporates healthy fats.
Fortified Dairy	Milk, Yogurt	Varies (e.g., 120 IU in 1 cup fortified milk)	Common dietary source for many people.
Fortified Grains	Cereals, Oatmeal	Varies (e.g., 80 IU in 1 serving of fortified cereal)	Easy way to incorporate into breakfast.
Other Sources	Egg Yolks, Beef Liver, Mushrooms (UV-exposed)	Varies (e.g., 44 IU in 1 scrambled large egg)	Good dietary additions, especially for non-fish eaters.
Sunlight	Direct Exposure	Hard to quantify	Primary natural source, but requires caution.

In addition to ensuring sufficient vitamin D, practicing smell training can help. This involves deliberately and repeatedly sniffing a set of different scents (e.g., lemon, rose, eucalyptus, clove) to help retrain the brain to recognize odors. This technique is often used for post-viral smell loss but can be a beneficial exercise for general olfactory health.

Conclusion

Recent scientific studies, including large population-based surveys and animal research, have established a compelling link between vitamin D status and the health of the olfactory system. Vitamin D deficiency is associated with a higher prevalence of smell impairment, and some clinical observations suggest that supplementation can lead to recovery in individuals with existing deficiencies. The mechanisms likely involve vitamin D's neuroprotective, anti-inflammatory, and gene-regulating actions on the central nervous system and olfactory bulb. While correcting a deficiency through diet, sunlight, or supplements is a promising and low-cost intervention, it is crucial to consult a healthcare professional for a proper diagnosis and treatment plan, especially since other factors can also cause olfactory dysfunction.

For more information on vitamin D and its functions, refer to the National Institutes of Health Fact Sheet on Vitamin D.

Frequently Asked Questions

Yes, studies have shown a significant association between vitamin D deficiency and olfactory dysfunction, particularly age-related smell loss. Vitamin D is important for the nervous system, and its deficiency may negatively affect the neural pathways involved in smell.

It is best to consult a healthcare professional before starting supplementation. If a blood test confirms you have a vitamin D deficiency, your doctor may recommend supplementation, and some evidence suggests this can help improve smell function.

Vitamin D acts as a neurosteroid, binding to receptors in the olfactory network of the brain. It plays a neuroprotective role, influences neuronal growth, and helps regulate neurotransmitter systems, all of which are critical for processing smells.

Yes, in addition to vitamin D, deficiencies in other nutrients, particularly zinc and vitamin B-12, have also been linked to impaired taste and smell. A balanced diet is important for overall sensory health.

Smell training involves sniffing different scents regularly (e.g., lemon, clove, eucalyptus) to stimulate the olfactory receptors and help retrain the brain to recognize odors. It has shown varying degrees of success, especially for post-viral smell loss.

Excellent food sources of vitamin D include fatty fish like salmon and sardines, cod liver oil, and fortified foods such as milk, cereal, and orange juice. Mushrooms exposed to UV light also contain significant amounts.

No, it is not a guaranteed cure, as the cause of anosmia can be complex and multifactorial. While correcting a deficiency may help, especially in cases linked to inflammation or neurological issues, it depends on the underlying reason for the smell loss.