Effect of Low Level Laser Therapy on serum vitamin D and magnesium levels in patients with diabetic peripheral neuropathy - A pilot study

Diabetes Metab Syndr. 2019 Mar-Apr;13(2):1087-1091. doi: 10.1016/j.dsx.2019.01.022. Epub 2019 Jan 18.


Background: Diabetic Peripheral neuropathy (DPN) is the most distressing complication of diabetic population leading to loss of sensation, pain, and amputation. Low-level laser therapy (LLLT) has been used to manage nerve injuries as it holds the potential to induce a biostimulatory effect with no side effects. Hence we planned to study the biochemical effect and therapeutic outcomes of LLLT on patients with painful diabetic peripheral neuropathy as a preliminary work.

Materials and methods: Pre-posttest analysis was done on 40 patients diagnosed with DPN confirmed using 10 g Monofilament test and Michigan Neuropathy Screening Instrument (MNSI). Vibration sensation and pain measured by Vibration perception threshold (VPT) and Numeric pain rating scale (NPRS). All patients were given LLLT (3.1 J/cm2) on plantar and dorsal of the foot for 10 days. Serum samples were collected at baseline and 4 weeks after LLLT to estimate Vitamin D and Magnesium and compared the results.

Results: There was a significant increase in Vitamin D and Magnesium levels after LLLT. We observed a considerable improvement in the quality of life after LLLT demonstrated by a decrease in VPT and MNSI and a reduction in NPRS in DPN patients.

Conclusion: In this study, we found that LLLT improved the QL and hence may be a useful therapeutic option in treating peripheral neuropathic pain in type 2 diabetic patients. The progress in the serum Magnesium and Vit. D levels were proportional to the QL and may be a good indicator of the prognosis of DPN after LLLT.

Keywords: Diabetic peripheral neuropathy; Low-level laser therapy; Neuropathic pain; Serum magnesium; Vitamin D.

MeSH terms

  • Adult
  • Aged
  • Biomarkers / blood*
  • Diabetes Mellitus, Type 2 / complications*
  • Diabetic Neuropathies / blood
  • Diabetic Neuropathies / etiology
  • Diabetic Neuropathies / radiotherapy*
  • Female
  • Follow-Up Studies
  • Humans
  • Low-Level Light Therapy / methods*
  • Magnesium / blood*
  • Male
  • Middle Aged
  • Pilot Projects
  • Prognosis
  • Prospective Studies
  • Quality of Life*
  • Vitamin D / blood*
  • Vitamins / blood


  • Biomarkers
  • Vitamins
  • Vitamin D
  • Magnesium