Comprehensive review of melatonin as a promising nutritional and nutraceutical supplement.

Background: Melatonin is an indoleamine hormone secreted by the pineal gland at night and has an essential role in regulating human circadian rhythms (the internal 24-h clock) and sleep-wake patterns. However, it has recently gained considerable attention for its demonstrated ability in disease management. This review discusses the major biological activities of melatonin, its metabolites as nutritional supplements, and its bioavailability in food sources. Methods: The information acquisition process involved conducting a comprehensive search across academic databases including PubMed, Scopus, Wiley, Embase, and Springer using relevant keywords. Only the most recent, peer-reviewed articles published in the English language were considered for inclusion. Results: The molecular mechanisms by which melatonin induces its therapeutic effects have been the subject of various studies. Conclusion: While melatonin was initially understood to only regulate circadian rhythms, recent studies indicate that it has a far-reaching effect on various organs and physiological systems, such as immunity, cardiovascular function, antioxidant defense, and lipid hemostasis. As a potent antioxidant, anti-cancer, anti-inflammatory, and immunoregulatory agent, multiple therapeutic applications have been proposed for melatonin.

Vitamin C and/or garlic can antagonize the toxic effects of cadmium on growth performance, hematological, and immunological parameters of growing Japanese quail.

This study used 300 1-day-old, sexless, developing chicks of Japanese quail to estimate the ability of vitamin C and/or garlic to antagonize the venomous influence of cadmium (Cd) on the hematological, immunological, and performance characteristics of developing Japanese quail. The quail was separated into 5 similar groups of 60 chicks apiece, and 6 duplicates (10 each) were given to each sub-group. The control group received a basal diet without any supplements. The Cd group was nourished with a basal diet of + 80 mg cadmium chloride (CdCl2)/kg diet. The 3rd group was fed a basal diet + 80 mg CdCl2/kg diet and complemented with a 200 mg Vitamin C (Cd + C)/kg diet. The 4th group was nourished with a basal diet + 80 mg CdCl2/kg diet and complemented by a 500 mg dried garlic powder (Cd + G)/kg diet. The 5th group was fed a basal diet + 80 mg CdCl2/kg diet, complemented by a 200 mg vitamin C/kg diet + 500 mg dried garlic powder (Cd + CG)/kg diet. Results showed that in the 5th group in which cadmium was added together with Vit C + garlic, there was an improvement in both live weight gain (1-42 d) and feed consumption (1-21 and 1-42 d ) compared to the group in which Cd was added alone. The addition of Vit C alone and together with garlic seems to completely improve the cadmium-related increase in alkaline phosphatase (ALP), and Aspartate aminotransferase (AST), and Malondialdehyde (MDA) levels when compared to the control. Compared to cadmium-polluted diets, quail that got cadmium and feed additives significantly reduced cadmium residue. In addition, the cadmium group's serum immunoglobulin M (IgM) level decreased significantly. These data imply that dietary supplementation with (C) or (G) may be beneficial in retrogressing the drop in immunoglobulin G (IgG) and IgM caused by Cd and minimizing Cd's deleterious influence on immunity.

The Impact of Vitamin D Status on COVID-19 Severity among Hospitalized Patients in the Western Region of Saudi Arabia: A Retrospective Cross-Sectional Study.

The coronaviruses disease 2019 (COVID-19) spreads continuously worldwide. The new vaccines and drugs have been approved. The prevention of disease is crucial, and some studies reveal the promising effect of alternative therapies such as vitamin D supplementations on COVID-19 prevention, but they still require sufficient evidence. Therefore, the current retrospective multicenter cross-sectional study aims to determine the primary association between the vitamin D status of hospitalized COVID-19 and its severity as well as mortality. A total of 197 COVID-19 were admitted at King Faisal Hospital, Al Noor Specialist Hospital in Makkah, and at Complex King Faisal Hospital in Taif in the Westering region of Saudi Arabia (SA) between June and August 2020. The demographic and clinical characteristics, laboratory tests included serum 25(OH)D and admission for intensive care unit (ICU), length of stay in the hospital, mechanical ventilation (MV) support, and mortality were recorded and analyzed. Vitamin D deficiency (25(OH)D < 20 ng/mL) was found in 73.10% of all study population. Multiple logistic regression was used after adjusted covariances such as age, gender, diabetes, hypertension, and chronic kidney disease (CKD). No statistically significant was shown for ICU admission [Odd Ratio, OR 1.25 (95% confidence interval, CI 0.41-3.88) p = 0.70], MV support [Odd Ratio, OR 3.12 (95% confidence interval, CI 0.74-13.21) p = 0.12] and mortality [Odd Ratio, OR 2.39 (95% confidence interval, CI 0.31-18.11), p = 0.40]. These data didn't support the association between serum 25(OH)D and the severity of the disease among hospitalized COVID-19 patients.