Associations between pre-infection serum vitamin D concentrations and Omicron COVID-19 incidence, severity and reoccurrence in elderly individuals

• Published in: Public health nutrition 2024-10, Vol.27 (1), p.e197, Article e197
• Main Authors: Chen, Jiangjie, Lu, Fangying, Shen, Bo, Xu, Hongfang, Chen, Yijun, Hu, Qi, Xu, Anpeng, Tung, Tao-Hsin, Hong, Dun
• Format: Article
• Language: English
• Subjects: 25-Hydroxyvitamin D; Aged; Aged, 80 and over; Biobanks; Blood pressure; Calciferol; China - epidemiology; Chronic illnesses; Chronic obstructive pulmonary disease; community nutrition; Comorbidity; COVID-19; COVID-19 - blood; COVID-19 - epidemiology; COVID-19 vaccines; Diabetes; Dietary supplements; Endocrine therapy; Epidemics; Female; Fever; Humans; Hypertension; Incidence; Incidence and reoccurrence rate; Infections; Intensive care; Kidney diseases; Male; Middle Aged; Older people; Omicron COVID-19; Pandemics; Pneumonia; Recurrence; Regression analysis; Regression models; Research Paper; Retrospective Studies; Risk Factors; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Severity of illness; Severity of Illness Index; Smoking; Tuberculosis; Ventilators; Viral diseases; Vitamin D; Vitamin D - analogs & derivatives; Vitamin D - blood; Vitamin D deficiency; Vitamin D Deficiency - blood; Vitamin D Deficiency - epidemiology; Vitamin deficiency
• ISSN: 1368-9800; 1475-2727; 1475-2727
• DOI: 10.1017/S1368980024001873

Previous studies suggest a link between vitamin D status and COVID-19 susceptibility in hospitalised patients. This study aimed to investigate whether vitamin D concentrations in elderly individuals were associated with their susceptibility to Omicron COVID-19 incidence, the severity of the disease and the likelihood of reoccurrence during the era of the post-'zero-COVID-19' policies in China. In this retrospective study, participants were categorised into three groups based on their 25(OH)D concentrations: deficiency (< 20 ng/ml), insufficiency (20 to < 30 ng/ml) and sufficiency (≥ 30 ng/ml). The demographic and clinical characteristics, comorbidities and the incidence rate, reoccurrence rate and severity of Omicron COVID-19 were retrospectively recorded and analysed by using hospital information system data and an online questionnaire survey. China. 222 participants aged 60 years or older from a health management centre. Our findings revealed significant differences in the incidence ( = 0·03) and recurrent rate ( = 0·02) of Omicron COVID-19 among the three groups. Participants with lower 25(OH)D concentrations (< 20 ng/ml) exhibited higher rates of initial incidence and reoccurrence and a greater percentage of severe and critical cases. Conversely, individuals with 25(OH)D concentrations ≥ 30 ng/ml had a higher percentage of mild cases ( = 0·003). Binary and ordinal logistic regression models indicated that vitamin D supplementation was not a significant risk factor for COVID-19 outcomes. In the elderly population, pre-infection vitamin D deficiency was associated with increased susceptibility to incidence, severity of illness and reoccurrence rates of Omicron COVID-19.