Vitamin D Levels in COVID-19 Outpatients from Western Mexico: Clinical Correlation and Effect of Its Supplementation

Abstract

Background: The immunomodulatory effects of vitamin D are known to be beneficial in viral infections; it is also known that its deficiency is associated with a prognosis more critical of Coronavirus Disease 2019. This study aimed to determine baseline vitamin D serum concentrations and the effects of its supplementation in asymptomatic or mildly symptomatic Coronavirus Disease 2019 outpatients. Methods: 42 outpatients were included, 22 of which received a supplement of 10,000 IU of vitamin D3 for 14 days; the remaining 20 outpatients were designated as a control group. Serum levels of transferrin, ferritin, vitamin D, and D-dimer were measured at baseline in both groups. After 14 days, serum levels of total vitamin D were determined in the supplemented group. Results: At baseline, only 19% of infected outpatients had vitamin D levels corresponding to sufficiency. All outpatients with vitamin D insufficiency had at least one symptom associated with the disease, while only 75% of patients with symptoms presented sufficiency. On the seventh and fourteenth day of follow-up, the supplemented group presented fewer symptoms with respect to those non-supplemented. A vitamin D3 dose of 10,000 IU/daily for 14 days was sufficient to raise vitamin D serum concentrations. Conclusions: Immunomodulatory effects of vitamin D appear to be linked to the development of symptoms in positive outpatients. Vitamin D supplementation could have significant benefits in the Western Mexican population.

Vitamin D supplementation and clinical outcomes in COVID-19: a systematic review and meta-analysis

“…Of the 13 studies, 10 were observational studies [7-10, 12-14, 22-24], while 3 were RCTs [11,15,25]. Relevant studies where clinical outcomes were not reported in terms of ICU admission or mortality were excluded [26][27][28].…”

COVID-19 and Vitamin D (Co-VIVID Study): a systematic review and meta-analysis of randomized controlled trials

“…We reviewed 755 articles for eligibility, 6 RCTs [14][15][16][17][18][19] comprising 551 COVID-19 patients were selected for final analysis (Fig. 1).…”

“…There were two multi-center [16,18] and four single center RCTs [14,15,17,19], one doubleblinded [16] and four registered clinical trials [14][15][16]18]. Vitamin D treatment was compared to placebo in two studies [16,17], non-vitamin control in three studies [14,15,19], and standard treatment comparator group in one study [18]. While Castillo et al [14] used calcifediol with an allocation ratio of 2:1; all other studies used cholecalciferol with an allocation ratio of 1:1.…”

“…In an RCT by Sánchez-Zuno et al [19] 42 mild COVID-19 patients were randomized to intervention arm (22 cases receiving 10000 IU of vitamin D 3 orally for 14 days) and comparator arm that receives no vitamin D3 (n=20). A stratified analysis based on the sufficient (≥30 ng/mL) and insufficient (<30 ng/mL) baseline vitamin status indicated a significantly increased number of COVID-19 symptoms in the later group (p=0.03).…”

“…None of the trials reported any adverse events due to vitamin supplementation. As there are only two and three trials respectively in the years 2020 [14,17] and 2021 [15,16,18,19] including small sample sizes, this meta-analysis strongly recommends for more RCTs for better evaluating the role of vitamin D in COVID-19 patients. Therefore, the evidence obtained upon completion of several ongoing trials [28] (CORONAVIT, COVITD-19, COVIDIOL, VIVID and COVIT-TRIAL) will be crucial in better determination on vitamin D in association with COVID-19.…”