Is there a relationship between Vitamin D (Vit D) levels and the severity of hidradenitis suppurativa (HS)?

Relationship Between Vitamin D Levels and Hidradenitis Suppurativa

There is evidence suggesting a relationship between vitamin D deficiency and hidradenitis suppurativa (HS), with studies showing that vitamin D supplementation may help improve HS symptoms in deficient patients, though this is not yet part of standard treatment guidelines.

Evidence for Vitamin D Deficiency in HS

• Recent research indicates that vitamin D deficiency is common in patients with HS:
  • A 2022 cross-sectional comparative study in Jordan found that all HS patients in their sample had vitamin D deficiency, with a mean level of 8.4 ng/ml 1
  • A 2024 literature review confirmed that across multiple studies, HS patients consistently exhibited hypovitaminosis D 2

Correlation with Disease Severity

• Evidence suggests that vitamin D levels may correlate with HS severity:
  • The 2024 literature review found that serum vitamin D levels negatively correlated with disease severity 2
  • This means that lower vitamin D levels were associated with more severe HS symptoms

Therapeutic Potential

• Limited but promising evidence exists for vitamin D supplementation:
  • According to the North American Clinical Management Guidelines for HS, Guillet et al. found that of 22 vitamin D-deficient patients with HS who received supplements to achieve normal levels, 63% achieved a 20% decrease in inflammatory nodules 3
  • However, the same guidelines state that "the evidence is insufficient to support routine use of vitamin D or zinc supplementation" 3
  • The 2024 review concluded there is "at least suggestive evidence that vitamin D supplementation could have a positive impact on the course of HS" 2

Current Guideline Recommendations

• Despite the emerging evidence, current guidelines do not strongly recommend vitamin D supplementation as standard treatment:
  • The North American Clinical Management Guidelines (2019) acknowledge the potential benefit but state insufficient evidence exists for routine supplementation 3
  • The British Association of Dermatologists guidelines (2019) do not specifically mention vitamin D supplementation for HS 3
  • Neither do the US and Canadian HS Foundations' guidelines on comorbidity screening specifically recommend vitamin D testing or supplementation 3

Associated Factors

• Several factors may connect vitamin D deficiency and HS:
  • Obesity is strongly associated with both HS (75% of patients) and vitamin D deficiency 3
  • Smoking is also highly prevalent in HS patients (70-75%) and may impact vitamin D metabolism 3
  • Chronic inflammation in HS may affect vitamin D metabolism or utilization

Clinical Implications

• While not yet in guidelines, clinicians might consider:
  • Checking vitamin D levels in HS patients, especially those with more severe disease 4
  • Supplementing vitamin D in deficient patients as an adjunctive treatment 4, 2
  • Addressing associated factors like obesity and smoking that may impact both conditions 3

Limitations and Future Directions

• Current evidence has limitations:
  • Most studies are observational rather than randomized controlled trials
  • Sample sizes tend to be small
  • The 2024 review specifically calls for "conducting a randomized controlled trial study on vitamin D and its effects on HS severity" 2

Practical Approach

1. Consider checking vitamin D levels in patients with HS, particularly those with moderate to severe disease
2. If deficiency is found, supplement according to standard vitamin D replacement protocols
3. Address modifiable risk factors like obesity and smoking that affect both conditions
4. Monitor for improvement in HS symptoms after vitamin D normalization
5. Consider vitamin D as an adjunct to standard HS treatments, not a replacement

While the relationship between vitamin D and HS is becoming clearer, more robust research is needed before vitamin D supplementation can be recommended as a standard treatment for HS.