Vitamin D for carpal tunnel syndrome symptoms

By Dr. Liji Thomas, MDReviewed by Benedette Cuffari, M.Sc.Jun 23 2024

A recent study published in the journal Nutrients explores vitamin D's role in managing carpal tunnel syndrome (CTS).

Study: The role of vitamin D in the treatment of carpal tunnel syndrome: clinical and electroneuromyographic responses. Image Credit: Alliance Images / Shutterstock.com

What is CTS?

CTS is among the most prevalent peripheral neuropathies affecting the wrist anatomy. It causes compression of the median nerve, a large nerve that innervates the arm, forearm, and hand. This compression causes the affected individual to feel pain, numbness, or tingling along the upper limb area affected by the pressure. Furthermore, CTS often leads to weakened grip and hand function.

Obesity, diabetes, repetitive stress injury, rheumatoid inflammation, pregnancy, and genetic factors interact to increase the risk of CTS. CTS typically affects those between 40 and 60 years; however, the condition can also affect individuals of other ages. Women are twice as likely to have CTS as men, with 193 and 88 women and men affected for every 1,000,000, respectively.

Vitamin D and CTS

Vitamin D is a fat-soluble vitamin that regulates calcium and phosphorus metabolism and immunologic function. It is also crucial for endocrine, cardiovascular, skeletal, and skin health and is associated with metabolic and antioxidant/anti-inflammatory properties.

Thus, vitamin D deficiency could potentiate several neuropathic or pain syndromes associated with increased inflammation. Vitamin D deficiency also enhances symptom severity in CTS.

To date, it remains unclear how vitamin D supplementation could help manage CTS.

About the study

The current study included 14 patients with CTS from two centers. All study participants had CTS on one or both wrists and low vitamin D levels. None of the study participants had consumed vitamins for six months before the study period, nor did any of the participants have a history of medical or surgical treatment for CTS.

The study participants were screened for other conditions that could cause CTS or similar symptoms, such as neuropathies, inflammatory syndromes, trauma in the affected limb, poorly managed diabetes, disease of the thyroid and parathyroid, cervical problems, and obesity. All study participants were females with a mean age of 51 years.

The participants were randomized to receive either corticosteroid therapy alone or corticosteroids with vitamin D supplementation. Block randomization was utilized to ensure homogeneity within the cohort.

Graphical Abstract

What did the study show?

Among CTS patients with low vitamin D levels, the addition of vitamin D to corticosteroid therapy led to improved pain relief, reduced symptom severity, and certain electromyography (EMG) parameters.

At baseline, Phalen and Tinel tests were conducted on all patients, with 86% and 71% positivity rates, respectively. When stratified by group, the intervention group had 100% Phalen positivity at baseline, which was reduced to 75% at three months. Comparatively, Phalen positivity rates in the corticosteroid treatment alone group were 67% and 33%, respectively.

At baseline, corticosteroid-only recipients had 50% positivity on the Tinel test, which was reduced to 33% by three months. Compared to baseline levels of 88%, vitamin D supplementation led to Tinel test positivity of 75% by three months.

Pain relief was greater in the intervention group than in the controls, which corresponds to the increased vitamin D concentrations. Symptom severity was reduced in both groups without significant functional state improvement.

With EMG, motor latency of the median nerve and sensitive driving speed improved in the intervention group.

Conclusions

Previous studies have indicated that vitamin D deficiency increases the risk of CTS and symptom severity. The current study corroborates these results and suggests that vitamin D supplementation in CTS patients with low vitamin D levels may reduce innervation and hypersensitivity levels, thereby reducing pain sensation and nerve tingling. Lower vitamin D levels were associated with greater symptom severity, which improved after three months of supplementation alongside corticosteroid therapy.

Vitamin D protects against neuropathies like CTS by suppressing L-type calcium channel expression and upregulating vitamin D receptors and their antioxidant activity.

Vitamin D supplementation improves pain severity in CTS. In addition, it influences the reduction in the severity of symptoms in patients with CTS, but it does not interfere with their functional status.”

Both Tinel and Phalen tests, though typically used for diagnosis rather than monitoring treatment, showed clinical improvement in both groups. Thus, the current study also demonstrates a monitoring role for these tests.

Future studies with larger sample sizes, longer follow-up, and other evaluation tools are indicated to validate and extend the results of this experiment.