title: Is vitamin D deficiency a cause of increased morbidity and mortality at older age or simply an indicator of poor health?
abstract: To assess whether vitamin D deficiency is a cause of increased morbidity and mortality or simply an indicator of poor health, we assessed (1) the cross-sectional and longitudinal association of vitamin D deficiency with self-rated health (SRH) and frailty and (2) the association of vitamin D deficiency with mortality, with and without control for SRH and frailty. Analyses were performed in 9,579 participants of the German, population-based ESTHER cohort (age-range at baseline: 50-74 years), with follow-ups after 2, 5 and 8 years (mortality: 12 years). During follow-up, 129 subjects newly reported poor SRH, 510 developed frailty and 1,450 died. In cross-sectional analyses, subjects with vitamin D deficiency had higher odds of a poor SRH and frailty but no association with SRH or frailty was observed in longitudinal analyses. The association of vitamin D deficiency with all-cause and several cause-specific mortalities was strong and unaltered by time-dependent adjustment for classic mortality risk factors, SRH and frailty. In conclusion, vitamin D deficiency may not cause frailty or poor general health but may nevertheless be a prognostic marker for mortality, independent of the individual's morbidity.
authors.affiliation: Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Im Neuenheimer Feld 581, 69120, Heidelberg, Germany, b.schoettker@dkfz.de.
authors.forename: Ben
authors.initials: B
authors.lastname: Schöttker
authors.forename: Kai-Uwe
authors.initials: KU
authors.lastname: Saum
authors.forename: Laura
authors.initials: L
authors.lastname: Perna
authors.forename: José Manuèl
authors.initials: JM
authors.lastname: Ordóñez-Mena
authors.forename: Bernd
authors.initials: B
authors.lastname: Holleczek
authors.forename: Hermann
authors.initials: H
authors.lastname: Brenner
mesh_terms: D000368:Aged; D002423:Cause of Death; D003430:Cross-Sectional Studies; D005260:Female; D016330:Frail Elderly / Q000706:statistics & numerical data; D015577:Geriatric Assessment / Q000379:methods*; D005858:Germany / Q000453:epidemiology; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D009017:Morbidity / Q000639:trends*; D009026:Mortality / Q000639:trends*; D011237:Predictive Value of Tests; D015995:Prevalence; D012307:Risk Factors; D057566:Self Report; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D013997:Time Factors; D014808:Vitamin D Deficiency / Q000097:blood* / Q000401:mortality