Table 3.

Non-Pharmacological Treatments: Vitamin D.

First Author Year (Ref)	Number of Participant (M/F)	Age (y)	Setting	Inclusion Criteria	Exclusion Criteria	Supplement		Duration	Results	Conclusion
						Intervention	Control
Knutsen et al., 2010 [35]	166/406	NR	Health center in which seven GPs serve 6200 patients (multi-ethnic area -north-eastern Oslo)	Analyzed Vitamin D levels in patients with headaches, fatigue, local or systemic muscle pain disease	Osteoporosis, injury, spinal herniation, rheumatic disease, and migraine	NR	NR	2 years	A total of 58% patients had low vitamin D levels (<50 nmol/L). Women had a higher degree of hypovitaminosis D than men (less than 30 nmol/L: p = 0.0005 and less than 25 nmol/L: p = 0.021). Headache was still significantly associated with hypovitaminosis D (p = 0.008, OR 2.6) after adjustment for gender, season, geographic region of origin, and age	The lowest levels of vitamin D were found among patients complaining of headaches
McCabe et al., 2016 [40]	3369 M	40–79	European Male Ageing Study	European Male Ageing Study With pain and vitamin D status	European Male Ageing Study without pain	Questions about lifestyle, including smoking and frequency of alcohol consumption and outdoor exercise. Pain level and localization. Serum levels of 25-(OH)D	NR	4.3 years	After adjustment for age and centre, compared to those in the upper quintile of 25-(OH) D (>36.3 ng/mL) those in the lowest quintile (<15.6 ng/mL) were more likely to develop CWP (OR  =  2.32; 95% CI  =  1.27–4.23	The men in the lowest quintile at baseline were more likely to develop CWP at follow-up than those in the upper quintile of serum 25 (OH) D, but this seem linked to the presence of harmful health factors, in particular obesity and depression. No statistical association was observed between 1,25 (OH)2D and the new occurrence of CWP (chronic widespread pain)
Plotnikoff and Quigley 2003 [42]	150 M/F	10–65	Community University Health Care Center (Minneapolis)	People with nonspecific musculoskeletal pain	NR	Vitamin D assay	NR	2 years	The prevalence of hypovitaminosis D was unexpectedly high in this population of nonelderly, non-house bound, primary care outpatients with persistent, nonspecific musculoskeletal pain refractory to standard pharmaceutical agents. Of all patients, 93% (140/150) had deficient levels of vitamin D (mean, 12.08 ng/mL; 95% confidence interval [CI], 11.18–12.99 ng/mL)	More than 90% of the patients in this study with persistent, nonspecific musculoskeletal pain were found to have deficient levels of 25-hydroxyvitamin D (this study also showed an unexpected disparity in hypovitaminosis D severity: younger patients had significantly lower 25-hydroxyvitamin D levels than did older patients)

NOTES: CWD, chronic widespread pain. CI, confidence intervals; NR, not reported.