TABLE 2.
Primary articles relating to COVID‐19 and micronutrients, sleep and micronutrients, or inflammation and micronutrients
| Author and Year | Micronutrient | Study design | Study population | Result | Length of follow‐up period |
|---|---|---|---|---|---|
| COVID‐related articles | |||||
| Patel et al. (2021) | Zinc | Double‐blinded, randomized controlled trial | 15 participants received IV zinc, 18 patients received placebo | COVID‐19 patients showed zinc deficiency which appears to be corrected with high dose IV zinc | Maximum of 7 days, until hospital discharge or death |
| Demir et al. (2021) | Vitamin D | Retrospective cohort study | 227 COVID‐positive patients, 260 negative | Low vitamin D levels (<30 ng/ml) in 94.27% of COVID‐positive patients. Severe vitamin deficiency (<10 ng/ml) more common in COVID‐positive participants (44%); The group of COVID‐19 positive patients with vitamin D levels >30 ng/mL showed lower CRP and d‐dimer levels | N/A |
| Hernández et al. (2021) | Vitamin D | Retrospective case–control study | 216 COVID patients (with 19 on vitamin D supplements), 197 participants in control group | 82.2% of COVID‐positive participants had vitamin D deficiency. Serum 25OHD levels were lower in hospitalized COVID‐19 patients compared with population controls | N/A |
| Sleep‐related or CSF articles | |||||
| Cherasse et al. (2015) | Zinc | Experimental study | Mice administered zinc‐containing yeast | Increased NREM sleep and decreased locomotor activity | Locomotor activity tracked each hour after yeast administration, time spent in REM, NREM, and wakefulness tracked 4 hours after yeast administration |
| Gholipour Baradari et al. (2018) | Zinc | Double‐blinded, randomised controlled trial | 54 ICU nurses; 27 receiving zinc sulphate capsules, 26 placebo | Sleep quality (measured using Pittsburgh Sleep Quality Index), sleep latency, and serum zinc concentrations improved with zinc supplementation | 1 month |
| Grandner et al. (2013) | Zinc | Observational study | 5587 participants | Less than 5 hours of sleep was associated with decreased mineral intake, after adjustment for overall diet | N/A |
| Maes et al. (2006) | Zinc | Observational study | CFS patients and normal participants | Decreased serum zinc concentrations and increased inflammatory markers/oxidative stress in CFS patients | N/A |
| Saito et al. (2017) | Zinc | Double‐blinded, randomised, controlled, parallel‐group trial | 120 healthy subjects randomly assigned placebo or zinc‐rich group | The zinc‐rich food group decreased the time needed to fall asleep and demonstrated improved sleep efficiency. The group that was given zinc‐enriched yeast and astaxanthin oil showed significantly improved sleep onset latency. | 12 weeks |
| Jung et al. (2006) | Vitamin C | Experimental study | 19 patients who reported consistent fatigue, measured fatigue scores before and after IV vitamin C treatment | Decreased fatigue scores after IV vitamin C administration | 4 weeks of treatment, then follow‐up questionnaire |
| Suh et al. (2012) | Vitamin C | Double‐blinded, randomised, controlled clinical trial | 141 healthy volunteers | IV vitamin C decreased fatigue 2 hours post‐administration and until next day | Two hours after vitamin C administration, and follow‐up one day after |
| Nowak et al. (2016) | Vitamin D | Double‐blind placebo‐controlled clinical trial | 120 vitamin D‐deficient individuals with fatigue; randomised into placebo or vitamin D supplement groups | Decreased fatigue assessment scores in vitamin D group | 4 weeks post‐vitamin D supplementation |
| Godos et al. (2020) | Polyphenols | Observational study | 1936 participants | Increased polyphenols in the diet is associated with improved sleep quality (measured using Pittsburgh Sleep Quality index) | N/A |
| Sathyapalan et al. (2010) | Polyphenols (flavonoids) | Double‐blinded, randomised, clinical pilot crossover study | Ten CFS patients | Reduced CFS symptoms associated with high‐polyphenol chocolate administration | 8 weeks of high‐polyphenol or low‐polyphenol chocolate, then 2 weeks of no treatment; another 8 weeks with other type of chocolate |
| Inflammation‐related articles | |||||
| Ou et al. (2020) | Vitamin C | Phase II clinical trial | Total of 97 lung cancer patients; 49 receiving intravenous vitamin C, 48 control | Increase in progression‐free survival and overall survival with IV vitamin C combined with modulated electrohyperthermia (mEHT) compared to best supportive care alone. Fatigue was decreased significantly between groups post treatment | Follow‐up after a median of 24 months |
| Zhang et al. (2012) | Vitamin D | Experimental study | Blood samples from healthy volunteers and mice | Vitamin D inhibits monocyte/macrophage proinflammatory cytokine production | N/A |
| Kowluru and Kanwar (2007) | Polyphenols (curcumin) | Controlled, experimental study | Diabetic rats receiving curcumin or placebo diet | A curcumin diet is associated with decreased diabetes‐induced pro‐inflammatory marker levels | 6 weeks |