Objectives:
Does vitamin D deficiency increase severity of COVID-19 infection?

Study design:
This review article included 17 observational studies with 2,756 COVID-19 patients.

Objectives:
The literature showed that grape products containing polyphenols (GPCP) had anti-oxidant activity. However, the effects of GPCP on different biomarkers of oxidative stress are still controversial. Therefore, this review article (meta-analysis) has been conducted.

Does supplementation of grape products containing polyphenols improve status of oxidative stress (like TAC, ORAC and SOD)?

Study design:
This review article included 17 eligible RCTs with a total of 633 participants.

Objectives:
Excess body weight, including overweight and obesity, is one of the major factors influencing human health and plays an important role in the global burden of disease. Carotenoids serve as precursors of vitamin A-related retinoids and are considered to have potential effects on many diseases. However, the influence of carotenoids on people with excess body weight is unclear. Therefore, this review article has been conducted.

Objectives:
The benefit of IVIG (Intravenous Immunoglobulin) therapy for COVID-19 remains controversial. Therefore, this review article has been conducted.

Does intravenous immunoglobulin therapy reduce mortality in patients with COVID-19?

Study design:
This review article included 4 RCTs and 3 retrospective cohort studies with a total of 825 hospitalized patients.

Overall, the quality of the 7 included studies was low.

Objectives:

Objectives:
Does spina bifida increase risk of neonatal and infant mortality?

Study design:
This review article included 20 population-based cohort studies conducted in high-income countries.
These studies included a total study population of over 30 million liveborn infants (median study sample size: 1,178,452 (251,699-14 million)) in which approximately 12,000 (median: 231 (27-3,903)) were affected by spina bifida.
All infants included were born at ≥20 weeks gestational age with a birthweight ≥500g.

Objectives:
The association of meat consumption with mortality and morbidity for non-communicable diseases has been extensively studied. However, the relation of white meat consumption with health outcomes remains controversial. Therefore, this review article has been conducted.

Objectives:
Does supplementation of thiamine (vitamin B1) combined vitamin C reduce mortality in patients with sepsis or septic shock?

Study design:
This review article included 7 randomized controlled trials (RCTs) with a total of 868 patients.

Objectives:
Preliminary retrospective reports showed that zinc supplementation may decrease mortality in COVID-19 patients, postulating the potential therapeutic efficacy of zinc in the management of the disease. Therefore, this review article has been conducted.

Objectives:
Patients with kidney failure often present with reduced cardiovascular functional reserve and exercise tolerance. Previous studies on cardiorespiratory fitness examined with cardiopulmonary-exercise-testing (CPET) in kidney-transplant-recipients (KTR) had variable results. Therefore, this review article has been conducted.

Does cardiovascular functional reserve improve after kidney-transplantation?

Study design:
This review article included 8 studies with 461 participants.