Severe vitamin D deficiency was found to be associated with lumbar degenerative disease and low back pain in postmenopausal women, according to study results published in Menopause.
Low vitamin D is common in postmenopausal women and may be associated with low back pain. Because limited data are available on the role of vitamin D in spinal degenerative diseases, the goal of the current study was to explore the relationship between low vitamin D levels and lumbar degenerative disease and low back pain in older women.
The retrospective observational study included 232 postmenopausal women (mean age, 65.5 years) with low back pain and lumbar degenerative disease who attended the spinal surgery unit in a single hospital. Most women had deficiency/insufficiency of vitamin D (>10 to <30 ng/mL; 173 women; 74.6%), whereas a small minority had severe deficiency (≤10 ng/mL; 30 women; 12.9%) or normal levels (≥30 ng/mL; 29 women; 12.5%).
There were substantial differences in circulating vitamin D concentrations between patients with normal bone density, osteopenia, or osteoporosis (21.62±9.42 vs 18.01±9.41 vs 17.39±8.17 ng/mL, respectively; P <.05). Bone mineral density T-scores were lower in the group of patients with severe vitamin D deficiency (-1.92±1.55) compared with those with deficiency/insufficiency (-1.19±1.35) or normal levels (-0.70±1.64; P =.004).
With regard to pain, the mean visual analog scale for low back pain was higher among patients with severe vitamin D deficiency (4.07±1.11) compared with those with vitamin D deficiency/insufficiency (3.54±1.11) or normal vitamin D (3.03±1.15; P =.002).
As for the association between lumbar degenerative disease severity and vitamin D concentrations, the statistical analysis revealed that from L1/L2 to L5/S1, patients with severe vitamin D deficiency had more severe disc degeneration compared with those with insufficiency/deficiency or normal concentrations, with evidence for significant differences at L4/L5 (P =.02), L5/S1 (P =.001), and L1/S1 (P =.04).
Analysis of risk factors for moderate to severe pain revealed that severe vitamin D deficiency was the strongest predictor (odds ratio [OR], 5.791; 95% CI, 1.57-21.38; P =.008). Other risk factors included vitamin D deficiency (OR, 3.03; 95% CI, 1.10-8.31; P =.032), osteoporosis (OR, 3.33; 95% CI, 1.39-7.94; P =.007), body mass index (OR, 1.18; 95% CI, 1.06-1.32; P =.004), smoking (OR, 4.18; 95% CI, 1.12-19.89; P =.035), and lack of vitamin D supplementation (OR, 2.85; 95% CI, 1.29-6.26; P =.009).
The researchers acknowledged several limitations of the study, including the retrospective design, relatively small sample size, inclusion of only Chinese women, and lack of quantitative measurements to determine the severity of lumbar degenerative disease.
“[A] serum concentration of vitamin D <10 ng/mL should be considered an indicator of severe disc degeneration and [low back pain],” the researchers concluded. Further research is needed to determine whether vitamin D supplementation is effective for the prevention and treatment of these conditions.
Xu HW, Yi YY, Zhang SB, et al. Does vitamin D status influence lumbar disc degeneration and low back pain in postmenopausal women? A retrospective single-center study [published online February 10, 2020]. Menopause. doi:10.1097/GME.0000000000001499