Objectives:
It is unclear how dietary intake influences the ovarian cancer. Therefore, this review article (meta-analysis) has been conducted.

Is there a relationship between dietary intake of different nutrients/food groups and ovarian cancer risk?

Study design:
This review article included 97 cohort studies.

Results and conclusions:
The investigators found no significant association between dietary intake and risk of ovarian cancer.

Objectives:
Is diabetes mellitus associated with severe infection and mortality in patients with COVID-19?

Study design:
This review article included 76 studies, involving 31,067 patients with COVID-19.

The number of confirmed COVID-19 cases in each study ranged from 41 to 3,841.
The proportion of diabetic patients ranged from 3.3 to 68.5%.
There was no statistically publication bias.

Objectives:
Depending on the epidemiological context of each country, three vaccines are recommended by the World Health Organization (WHO) to be administered as soon as possible after birth (birth vaccines); namely, BCG, zero dose of oral polio vaccine (OPV0) and birth dose of hepatitis B vaccine (HepB-BD). The timely administration of these vaccines immediately after birth might pose significant challenges in sub-Saharan Africa, where about half of childbirths occur outside health facilities. Therefore, this review article has been conducted.

Objectives:
Which treatment is associated with favorable outcomes in COV-2019 patients?

Study design:
This review article included 15 in-vitro and 35 clinical studies including 9,170 COVID-2019 patients.

Results and conclusions:   
The investigators found Lopinavir-Ritonavir was significantly associated with shorter mean time to clinical recovery [SMD = -0.32, 95% CI = -0.57 to -0.06].

Objectives:
How long does the incubation period of COVID-19 last?Study design:
This review article included 8 studies.

Objectives:
Iron metabolism and anemia may play an important role in multiple organ dysfunction syndrome in Coronavirus disease 2019 (COVID-19). Therefore, this review article has been conducted.

Objectives:
Patients with pre-existing cardiovascular disease (CVD) might be more susceptible to infection from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and have higher mortality rates. Nevertheless, the risk of mortality has not been previously quantified. Therefore, this review article has been conducted.

Which are the risk factors of mortality in coronavirus disease 2019 (COVID-19) patients?

Objectives:
The relationship between dietary pattern and the risk of chronic obstructive pulmonary disease (COPD) has been described; however, the exclusive role of dietary factors remains controversial. Therefore, this review article has been conducted.

Does a dietary intake of fruits and vegetables, dietary fiber, fish, n-3 or n-6 fatty acids and antioxidant vitamins reduce risk of COPD in adults?

Objectives:
Coronavirus disease 2019 (COVID-19) patients exhibited protean clinical manifestations. Olfactory and gustatory abnormalities (anosmia and ageusia) were observed in COVID-19 patients, but the reported prevalence varied. Therefore, this review article has been conducted.