High Prevalence of Vitamin D Insufficiency in the Elderly Population in Argentina

OLIVERI BEATRIZ; PLANTALECH L; BAGUR A; WITTICH AC; ROVAI G; PUSIOL E; LÓPEZ GIOVANELLI J; NIEVA A; CHAPERON A; LADIZESKY M; SOMOZA J; CASCO C; ZENI S

San Antonio - EEUU

Congreso; XXIV Congreso Anual de la ASBMR; 2002

American Society for Bone and Mineral Research

Vitamin D insufficiency is common in elderly populations ( mainly in subjects living in homes for theelderly) and leads to secondary hyperparathyroidism, high bone resorption, bone loss and osteoporoticfractures. The aim of this study was to evaluate the nutritional status of vitamin D in elderly people livingin their own homes in different cities in Argentina.350 ambulatory subjects older than 65 years ( X ± SD)(71.3± 5.2 years ),(236 women and 114 men) from7 cities in Argentina (between latitude 27ºS and 55ºS) were evaluated between the end of winter andbeginning of spring ( 15th August-15th October). None of the subjects was receiving vitamin D or anymedication that could affect mineral metabolism. They were grouped in 3 geographical regions: SouthRegion (Bariloche: 41ºS, n=28; Comodoro Rivadavia: 45ºS, n=30; Ushuaia:55ºS, n=32); Mid-region(Buenos Aires 34ºS, n=168; Mendoza:33ºS, n=33) and North Region (Corrientes: 27ºS, n=30; Tucumán:27ºS, n=30). Two patients were excluded because of primary hyperparathyroidism. Serum levels ofcalcium (Ca), creatinine (Cre) , bone alkaline phosphatase (BAP), 25(OH)D and mmPTH were measured.The results of 25(OH) D were analyzed as suggested by Mc Kenna (Osteoporosis Int 8, 1998):Deficiency(Def): <10 ng/ml; Insufficiency(Ins): >10-<20 ng/ml. The differences in 25(OH)D were thefollowing: the South Region exhibited the lowest levels (p<0.0001vs North and Mid regions): 14.3± 5.6ng/ml (Def:13%, Ins:75%), with the highest prevalence of deficiency in the southernmost city Ushuaia:25%. The highest levels of 25(OH)D were observed in the North (p<0.03 vs Mid, p<0.0001vs South):20.6 ± 7.4ng/ml (Def:2% Ins:50%). The Mid-region showed intermediate levels, between the South andNorth 17.8±8 ng/ml (Def:12% Ins:52%). Serum PTH and 25(OH)D were inversely related: r=-0.3,p<0.001). Serum levels of Ca(9.5±0.3mg/dl) BAP( 61.0±19UI/l)and Cre(0.9±0.2mg/dl) were withinnormal limits with no significant differences among regions.Conclusion: The risk of insufficiency increases as latitude augments. The high prevalence of lower winter25(OH) levels in this elderly urban population suggests the usefulness of vitamin D wintersupplementation to reduce osteoporotic fractures.