Table 2.

Ongoing randomized open-label and blinded trials of vitamin D supplementation in COVID-19 (NIH Trial Net database).

Name of Trial	Design	Start Date	End Date	Sample Size	Intervention	Outcome
Vitamin D on Prevention and Treatment of COVID-19 (COVITD-19) (NCT04334005)	Randomized, double-blind	April 10 2020	June 30 2020	200	Single dose of 25,000 IU of oral colecalciferol	Composite of cumulative death for all causes and for specific causes
Low-risk, Early Aspirin and Vitamin D to Reduce COVID-19 Hospitalizations (LEAD COVID-19) (NCT04363840)	Randomized open label parallel assignment	May 2020	December 2020	1080	Aspirin 81 mg orally daily for 14 days plus a dietary supplement of 50,000 IU of vitamin D orally once weekly for 2 weeks	Hospitalization for COVID-19 symptoms
Open Label Phase II Pilot Study of Hydroxychloroquine, Vitamin C, Vitamin D, and Zinc for the Prevention of COVID-19 Infection (HELP-COVID-19) (NCT04335084)	Randomized Double-Blind, Placebo-Controlled	April 2020	July 2020	600	Hydroxychloroquine for 1 day and a dietary supplement of vitamin C, vitamin D and Zinc for 12 weeks	Prevention of COVID-19 symptoms in medical workers who are at elevated risk of COVID-19 due to exposure to positive patients in the Emergency department or Intensive Care Unit
Impact of Zinc and Vitamin D3 Supplementation on the Survival of Aged Patients Infected with COVID-19 (ZnD3-CoVici) (NCT04351490)	Randomized open label parallel assignment	April 2020	July 2020	3140	Zinc Gluconate orally 15 mg X 2 per day, 25 -OH-colecalciferol drinkable solution 10 drops (2000 IU) per day for 2 months	Survival rate in subjects asymptomatic at inclusion time
COVID-19 and Vitamin D Supplementation in a Multi-center Randomized Controlled Trial of High Dose Versus Standard Dose Vitamin D3 in High-Risk COVID-19 Patients (CoVit Trial) (NCT04344041)	Randomized open label parallel assignment	April 2020	July 2020	260	Either a single dose of colecalciferol 400,000 IU compared to single dose of 50,000 IU	Number of deaths from any cause during the 14 days following inclusion and intervention
Prevention and treatment with Calcifediol of Coronavirus induced acute respiratory syndrome (SARS) COVID-19 (COVIDIOL) (NCT04366908)	Multi-center, randomized, open label parallel assignment	April 29 2020	August 28 2020	1008	Best available therapy plus Calcefediol 532 mcg orally on the day of admission and 266 mcg orally on day 3, 7, 14, 21 and 28 or Best available therapy only	Proportion of patients admitted to Intensive Care Unit or died at day 28
Preventive and Therapeutic Effects of Oral 25-hydroxyvitamin D3 on Coronavirus (COVID-19) in Adults (Oral 25-hydroxyvitamin D3 and COVID-19) (NCT04386850)	Multi-center, randomized, double-blinded, placebo-controlled clinical trial with parallel groups and allocation 1:1	April 14 2020	November 15 2020	1500	25 mcg of 25 OHD3 orally daily to case group and placebo to control group for 2 months. One arm of the study is for patients testing positive for COVID-19. Another arm is to evaluate the preventive potential of 25 mcg of 25OHD3 in health care providers and hospital workers with a negative test for COVID-19	Therapeutic efficacy of rapidly correcting vitamin D deficiency in adults with the use of 25-hydroxyvitamin D3 [25(OH)D3] for reducing the risk of acquiring the SARS-CoV-2 (COVID-19) viral infection and mitigating morbidity and mortality associated with COVID-19.
Improving Vitamin D status in the Management of COVID-19 (NCT04385940)	Randomized parallel assignment with quadruple masking	June 2020	December 2020	64	Subjects randomized to high-dose therapy will take 50,000 IU two times in the first week and once weekly over 2nd and 3rd weeks. Subjects in low -dose arm will take vitamin D 1000 IU daily for 3 weeks	To determine the relationship between baseline vitamin D deficiency and clinical characteristic and to assess patient response to vitamin D supplementation in week 3 and determine its association with disease progression and recovery