According to a recent study which was a 6-month retrospective study of 273,618 people infected with COVID-19, what some call ‘Long COVID’ only occurs with an overall excess incidence of 16.60% in COVID-19 VS Influenza.
For 9 core features of long-COVID; Breathing difficulties/breathlessness, fatigue/malaise, chest/throat pain, headache, abdominal symptoms, myalgia, other pain, cognitive symptoms, and anxiety/depression, the study says occurred and co-occurred frequently and showed some specificity to COVID-19, though they were also observed after influenza.
The study concludes though that all 9 features were more frequently reported after COVID-19 than after influenza, but with an overall excess incidence of only 16.60%.
The study though does have limitations.
“The limitations of this study include that (i) the findings do not generalize to patients who have had COVID-19 but were not diagnosed, nor to patients who do not seek or receive medical attention when experiencing symptoms of long-COVID; (ii) the findings say nothing about the persistence of the clinical features; and (iii) the difference between cohorts might be affected by one cohort seeking or receiving more medical attention for their symptoms.”
Other studies suggest that high vitamin D levels reduce the likelihood of more severe COVID-19 symptoms.
One study found that among COVID-19-positive patients, the group with vitamin D levels of more than 30 ng/ml had significantly lower hospital stays, and no difference was found among the groups in terms of age and gender distribution.
The study also found that elevated vitamin D levels could even decrease COVID-19 PCR positivity.
Many media outlets, as well as politicians, have been highlighting the higher death rate from coronavirus for black Americans than White and Asian Americans, but differing vitamin D levels and obesity are likely the culprit.
According to the CDC the death rate from diabetes is highest among non-Hispanic black adults and lowest among non-Hispanic white adults. During 2004–2017, the death rate decreased from 438.3 per 100,000 to 391.1 among non-Hispanic white adults, from 602.0 to 485.7 among Hispanic adults, and from 804.3 to 607.0 among non-Hispanic black adults.
But still much higher for Hispanic and Black adults than any other group.
Data from the National Health and Nutrition Examination Survey (NHANES) III shows that non-Hispanic blacks are at more than 10 times greater risk than non-Hispanic whites of being in the lowest quartile of 25(OH) vitamin D serum measurements. Hispanics have 2.5 times the risk, and other races have 3 times the risk.