Vitamin D defiency during pregnancy is a major public health problem worldwide; In Spain, the average intake of vitamin D is lower than recommendations in an elevated percentage of the population, ranging from 50 to 95%, according to the Spanish Society of Community Nutrition (SENC). Recent research suggests that adverse pregnancy outcomes are associated to vitain D deficiency. Associated comorbidities are further complicated by the SARS-COV-2 Pandemic. Few studies have assessed the transmission of SARS-CoV-2 antibodies from mothers who have had the disease or have been vaccinated to their newborns, either at birth or during breastfeeding, or how vitamin D concentration influences the generation of such an immune response. The COVID-19 pandemic is a dynamic situation. Peer-reviewed studies in large study cohorts point to a clear relationship between prevalence and severity of COVID-19 and vitamin D deficiency.

Researchers propose a randomized, non-blinded clinical trial in pregnant women recruited at the obstetrics and gynecology service of the Virgen de las Nieves University Hospital Granada during the appointment of the first gynecological control visit (weeks 10-16 of pregnancy). The woman participating in the study will be assigned to two randomized follow-up groups, intervention group that will be supplied with 1.000 IU of vitamin D and control group with 400 IU of vitamin D.All pregnant women who want to participate in the study but do not wish to supplement, will be part of another group, the unsupplemented control group. Participants will take the supplementation from 10-16 weeks of gestation to delivery. The frequency of gybecological visits will coincide with their routine prenatal visits: weeks 10-16, weeks 20-24 and weeks 34-36 of gestation. During the entire duration of the study, pregnant women will be in touch with the health professionals through routine hospital controls.

The present study was approved by the Ethics Commitee CEIM/CEI of Granada, Spain.

• INCLUSION CRITERIA:
• Pregnant women
• Over 18 years of age.
• Attendance at the hospital complex and intending to give birth in public centres in the province of Granada.
• With the capacity to understand and sign the informed consent form.
• EXCLUSION CRITERIA:
• Consumers of vitamin complexes.
• Co-infection with other infectious viruses or bacteria (HCV, HBV, HIV, among others).
• Severe respiratory symptoms that prevent participation in the study.