Vitamin D levels in older healthy Chilean adults and their association with functional performance

Background: People over 60 years old are at risk of Vitamin D deficiency, which can affect functional performance, since this vitamin is involved in muscle function and protein synthesis. Aim: To measure 25OH vitamin D levels in healthy older people from Santiago de Chile, and evaluate their relationship with functional performance. Subjects and Methods: Healthy subjects aged 60 years or more and living in the community were invited to participate. People with chronic diseases, cognitive impairment, physical disability, smokers and those consuming more than three medications per day were excluded. Hand grip and gait speed were measured and a blood sample was obtained to measure 25OH vitamin D by radioimmunoanalysis. Results: One hundred and four participants aged 60 to 98 years (55% females) were studied. Mean vitamin D levels were 17.3 +/- 6.1 ng/mL. Females had lower levels than males (15.6 +/- 5.8 and 19.2 +/- 6.0 ng/mL respectively p < 0.01). Eighty three percent of females and 55.3% of males had values below 20 ng/mL (the cutoff point for deficiency). Only 3.5% of females and 8.5% of males had values of 30 ng/ml or higher. There was a significant correlation between vitamin D levels, gait speed and grip strength (r = 0.32 and 0.34 respectively, p < 0.01), especially in women over 74 years. Conclusions: Vitamin D deficiency is almost universal in healthy adults over 60 years living in Santiago de Chile, especially in women. This deficiency is associated with a deranged functional performance and is a potentially modifiable risk factor for disability.