Insufficient levels of serum 25-hydroxyvitamin D (25[OH]D) appear to be a major contributor to deaths in older adults, as shown in a study showing vitamin D levels to be inversely proportional to mortality risk in these individuals (J Am Geriatr Soc. 2009;57:1595-1603).
“The association was strong (two times greater odds of mortality for 25[OH]D level <25.0 nmol/L) and appeared linear within the range of the data and independent of common CVD [cardiovascular disease] and mortality risk factors,” researchers note.
The team looked at the vitamin D levels of 3,408 men and women aged 65 years and older upon their enrollment in the Third National Health and Nutrition Examination Survey (NHANES III). After a median 7.3 years of follow-up, 1,493 (44%) of the cohort had died. Slightly more half the deaths (767) were CVD-related.
Compared with participants who had optimal vitamin D status, those who had low vitamin D levels were three times more likely to die from heart disease and 2.5 times more likely to die from any cause. Individuals with baseline 25(OH)D levels <50.0 nmol/L seemed to be at highest risk for mortality, “but levels of 100.0 nmol/L or greater may be necessary for better survival,” researchers observe.”