This study examined the relationships between sleep quality, anxiety, depression, musculoskeletal pain (MSP), and calcium intake. Design and Methods: In this cross-sectional study (N = 1422), sleep was assessed using the Pittsburgh Sleep Quality Index, anxiety and depression were assessed using the Hospital Anxiety and Depression Scale, and calcium intake and MSP were assessed by self-reporting. Findings: Poor sleep quality was reported by 62.66% of the participants. The participants with poor sleep quality reported lower calcium intake, higher anxiety and depression levels, more severe MSP, and multisite pain. Anxiety, depression, low calcium intake, and multisite pain were significant predictors of poor sleep quality. Anxiety was predicted by poor sleep quality, depression, multisite pain, and sex (ie, female). Depression was predicted by anxiety, poor sleep quality, and low calcium intake. Practical Implications: The findings underscore the role of low calcium intake in the development of sleep problems, anxiety, depression, and MSP. Individuals with these conditions should be advised to increase their calcium intake.

Objective: To assess dairy Ca intake and investigate its relationship with insomnia and other common co-morbidities including anxiety, depression and musculoskeletal pain (MSP) among university students. Design: Cross-sectional study. Setting: University, Irbid, Jordan. Participants: Male and female individuals (n 1000), aged 20·87 ± 2·69 years. Results: Low dairy Ca intake (<1000 mg/d) was reported by 96·5 % of participants, and moderate to severe insomnia reported by 15·6 % of participants. Abnormal anxiety and depression scores were reported by 26·2 and 18·0 % of participants, respectively. MSP was reported by 42·9 % of participants. Participants with moderate to severe insomnia had lower dairy Ca, higher anxiety and depression scores and higher measures of MSP compared to participants with no insomnia (P-values < 0·05). Dairy Ca was weakly inversely correlated with Insomnia Severity Index (ISI) score, depression score and measures of MSP (P-values < 0·05). Regression analysis indicated that insomnia was predicted by low dairy Ca, anxiety, depression, MSP and smoking (P-values < 0·05). Both anxiety and depression were predicted by increased ISI score (P-values < 0·05), while depression alone was predicted by low dairy Ca (P-value < 0·01). MSP was predicted by increased ISI and anxiety scores (P-values < 0·05). Conclusions: Low dairy Ca was highly prevalent and associated with insomnia and depression among university students. Individuals should be advised to increase dietary Ca intake to achieve the recommended daily amount. Further research is required to investigate a potential causal relationship between low Ca and both insomnia and its related co-morbidities.