The Vitamin D Serum Levels in Pregnant Women Affected by COVID-19: A Systematic Review and Meta-Analysis.

Vitamin D can modulate immune responses, and its deficiency is linked to increased autoimmunity and susceptibility to infection. In the general population, it has been observed that serum vitamin D levels are connected with the risk of COVID-19 and its severity. Our study aims to examine reported findings on the effect of vitamin D serum levels on infection of COVID-19 during pregnancy. PubMed, Web of Science, Embase, and Cochrane Library were searched for relevant studies. Serum vitamin D serum levels in COVID-19-positive and COVID-19-negative pregnant women were 24.61 ± 20.86 ng/mL and 24.12 ± 17.33 ng/mL, respectively. In mild vs. moderate to critical COVID-19 pregnant women, vitamin D serum levels were 16.71 ± 9.04 ng/mL vs. 10.7 ± 9.37 ng/mL and severe vs. non-severe were 13.21 ± 11.47 ng/mL vs. 15.76 ± 10.0 ng/mL. Only one study reported vitamin D serum levels in the placenta of COVID-19-positive pregnant women compared with the control and results varied and amounted to 14.06 ± 0.51 ng/mL vs. 12.45 ± 0.58 ng/mL, respectively. Vitamin D deficiency tends to be common in pregnant women who have COVID-19, and the level of this vitamin has been demonstrated to have a strong correlation with the severity of the illness. As vitamin D serum levels correlate with COVID-19 symptoms and even with its occurrence, appropriate vitamin D supplementation in the prenatal period is suggested.

Vitamin D supplementation to treat SARS-CoV-2 positive patients. Evidence from meta-analysis.

BACKGROUND: Vitamin D is a likely candidate for treatment as its immune modulating characteristics have effects on coronavirus disease 2019 (COVID-19) patients. It was sought herein, to summarize the studies published to date regarding the vitamin D supplementation to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive patients. METHODS: A systematic review and meta-analysis were performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The primary outcome were 14-day and in-hospital mortality reported as an odds ratio (OR) with the associated 95% confidence interval (CI). RESULTS: Eight articles were included in the review with a combined total of 2,322 individual patients, 786 in the vitamin D supplementation group and 1,536 in the control group. The use of vitamin D compared to the group without vitamin D supplementation was associated with a lower 14-day mortality (18.8% vs. 31.3%, respectively; OR = 0.51; 95% CI: 0.12-2.19; p = 0.36), a lower in-hospital mortality (5.6% vs. 16.1%; OR = 0.56; 95% CI: 0.23-1.37; I2 = 74%; p = 0.20), the rarer intensive care unit admission (6.4% vs. 23.4%; OR = 0.19; 95% CI: 0.06-0.54; I2 = 77%; p = 0.002) as well as rarer mechanical ventilation (6.5% vs. 18.9%; OR = 0.36; 95% CI: 0.16-0.80; I2 = 0.48; p = 0.01). CONCLUSIONS: Vitamin D supplementation in SARS-CoV-2 positive patients has the potential to positively impact patients with both mild and severe symptoms. As several high-quality randomized control studies have demonstrated a benefit in hospital mortality, vitamin D should be considered a supplemental therapy of strong interest. Should vitamin D prove to reduce hospitalization rates and symptoms outside of the hospital setting, the cost and benefit to global pandemic mitigation efforts would be substantial.

A systematic review and meta-analysis of effect of vitamin D levels on the incidence of COVID-19.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a disease primarily affecting the respiratory tract, however due to the nature of the pathogenesis it is able to affect the whole body. So far, no causative treatment has been found and the main strategy when dealing with COVID-19 relies on widespread vaccination programs and symptomatic treatment. Vitamin D due to its ability to modulate the immunological system has been proposed as a factor playing role in the organism response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Therefore, we decided to perform this meta-analysis which aimed to establish a connection between vitamin D status and COVID-19 infection. METHODS: Study was designed as a systematic review and meta-analysis. PubMed, EMBASE, Web of Science, Cochrane Collaboration Databases and Scopus electronic databases were searched for relevant studies from database inception to May 10th, 2021. Mean differences (MDs) with their 95% confidence intervals (CI) were calculated. RESULTS: Thirteen studies providing data for 14,485 participants met the inclusion criteria. Mean vitamin D levels in SARS-CoV-2 negative patients was 17.7 ± 6.9 ng/mL compared to SARS-CoV-2 positive patients 14.1 ± 8.2 ng/mL (MD = 3.93; 95% CI 2.84-5.02; I2 = 99%; p < 0.001). CONCLUSIONS: Low serum vitamin D levels are statistically significantly associated with the risk of COVID-19 infection. Supplementation of vitamin D especially in the deficiency risk groups is indicated.