Determinants of Circulating Levels of Vitamin D in Elderly People in Buenos Aires City, Argentina

L. PLANTALECH; B. OLIVERI; H SALERNI; J POZZO; M ERCOLANO; M LADIZESKY; C CASCO; S.N. ZENI; J SOMOZA; J FASSI; A BAGUR

San Antonio

Congreso; XXIV Congreso Anual de la ASBMR; 2002

Elderly people, especially those living in overpopulated cities, are a susceptible population tohypovitaminosis D. The aim of this study was to investigate the winter serum level of 25 OH vitamin D(25OHD) in 169 healthy people aged 71.5 ± 5.4 years (113 women and 56 men), living in Buenos Aires(34°S), and its relationship with exposure to sunlight, vitamin D (D) food (fish) intake, housing, clothing–use of beach-clothes such as short sleeves, shorts, etc– (using a questionnaire adapted from theEURONUT SENECA study), and socioeconomic status (determined by a test provided by the AsociaciónArgentina de Marketing). 25OHD was measured by Incstar RIA (ng/ml), none of the subjects receivedtreatment with D. Results: Mean 25OHD was :17.5 ± 4.5ng/ml . Forty nine percent of the subjects had noexposure to sunlight; 63% of the study population consumed rich D food. The socioeconomiccomposition of the study population was: 15.3% high (H), 35.7% middle (M) and 49.0% low(L) level:.Serum 25OHD was higher in people with high exposure to sunlight vs. no exposure (23.3 ± 2.1 vs. 15.3 ±0.1, p<0.001); who ate D food vs. zero intake ( 20.5 ± 1.7 vs. 15.2 ± 0.9,p<0.01) ; who lived in a housevs. apartment (19.2 ± 0.9 vs. 17.1 ± 1.3,p<0.05); who wore beach clothes in summer vs. long sleeves(20.9± 2.0 vs. 16.7 ± 0.7,p<0.01) and who had a high vs. low socioeconomic level (H: 20.7 ± 2.0 vs. L:.16.7 ±0.7, p<0.05). A linear correlation was observed between 25OHD and exposure to sunlight (r:0.35,p<0.001). A multistep regression analysis showed that both D food intake and exposure to sunlight arepredictors of levels of 25OHD (r2: 0.2, MSE:55.9, p<0.0001). Subjects in the high socioeconomic levelhad more exposure to sunlight (H: 5.5 ± 1.6 vs. M: 3.3 ± 0.6 vs. L: 1.4 ± 0.6 hours per week, p<0.03) andD food intake (H: 2.6 ± 0.2 vs. M: 1.7 ± 0.1 vs. L: 1.6 ± 0.1 time/week, p<0.0001) than those in themiddle or low level.Conclusion: Hypovitaminosis D is found in a high percentage of our elderly population and is associatedwith low exposure during sunlight and poor D food consumption. It is the people with scant economicresources that are most affected by these factors.