The role of vitamin D in the treatment of carpal tunnel syndrome

A recent study published in the journal Nutrients examines the role of vitamin D in the treatment of carpal tunnel syndrome (CTS).

Carpal tunnel syndrome (CTS) is one of the most common peripheral neuropathies affecting the anatomy of the wrist. It causes compression of the median nerve, a large nerve that supplies the arm, forearm, and hand. This compression causes the affected person to experience pain, numbness, or tingling along the upper limb that is subject to pressure. Additionally, CTS often results in a weakening of the grip and function of the hand.

Obesity, diabetes, repetitive strain injuries, rheumatoid arthritis, pregnancy, and genetic factors increase the risk of developing CTS. CTS usually affects people between the ages of 40 and 60, but the condition can also affect people of other ages. Women are twice as likely to have CTS as men: 193 women and 88 men per million population, respectively.

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

Thus, vitamin D deficiency may worsen several neuropathic or pain syndromes associated with increased inflammation. Vitamin D deficiency also increases the severity of CTS symptoms.

It remains unclear at this time how vitamin D supplementation may help treat CTS.

The present study included 14 patients with CTS from two centers. All study participants had CTS in one or both hands and low vitamin D levels. None of the participants had taken vitamins within six months prior to the study, and none had a history of medical or surgical treatment for CTS.

Study participants were screened for other conditions that can cause CTS or similar symptoms, such as neuropathies, inflammatory syndromes, trauma to the affected limb, poorly controlled diabetes, thyroid and parathyroid disease, cervical spine problems, and obesity. All study participants were women with an average age of 51 years.

Participants were randomly assigned to receive either corticosteroid therapy alone or corticosteroids plus vitamin D. Block randomization was used to ensure homogeneity within the cohort.

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

At baseline, Phalen and Tinel tests were performed on all patients, with positive results obtained in 86% and 71% of cases, respectively. In the vitamin D group, the percentage of positive Phalen tests decreased from 100% at baseline to 75% after three months. In the group receiving only corticosteroids, this figure decreased from 67% to 33%.

At baseline, 50% of the participants receiving corticosteroids alone had a positive Tinel test, which dropped to 33% after three months. In the vitamin D group, this rate dropped from 88% at baseline to 75% after three months.

Pain was reduced to a greater extent in the vitamin D group, consistent with the increase in vitamin D concentrations. Symptom severity was reduced in both groups, but no improvement in functional status was observed.

EMG showed improvements in motor nerve latency and nerve conduction velocity in the vitamin D group.

Previous studies have suggested that vitamin D deficiency increases the risk of developing CTS and the severity of symptoms. The present study confirms these findings and suggests that vitamin D supplementation in patients with CTS and low vitamin D levels may reduce innervation and hypersensitivity levels, thereby reducing pain and tingling. Low vitamin D levels were associated with greater symptom severity, which improved after three months of vitamin D supplementation along with corticosteroid therapy.

Vitamin D protects against neuropathies such as CTS by suppressing the expression of L-type calcium channels and increasing the activity of vitamin D receptors and their antioxidant activity.

Vitamin D supplementation improves pain severity in CTS. It also has an effect on reducing symptom severity in patients with CTS, but does not affect their functional status.

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

Future studies with larger samples, longer follow-up periods, and the use of other assessment instruments are needed to confirm and extend the results of this experiment.