Low levels of carotenoids and retinol in involutional osteoporosis.
Previous epidemiological studies conducted in retinol-supplemented subjects showed an association between high serum levels or dietary intake of retinol and risk of hip fracture. On the other side, observational studies revealed that non-supplemented subjects with higher dietary intake of retinol lose less bone with age than subjects with lower intake. This discrepancy, currently unexplained, suggests that nutrition plays a major role in conditioning the effects of retinol on bone. Since retinol is derived from both retinoids--contained in animal food--and carotenoids--contained in vegetables and fruits--we evaluated a possible role of carotenoids in involutional osteoporosis. Therefore, plasma levels of beta-carotene and other carotenoids, in addition to those of retinol, were measured in free-living, non-supplemented, elderly women with or without severe osteoporosis. Plasma levels of retinol and of all carotenoids tested, with the exception of lutein, were consistently lower in osteoporotic than in control women. A weak association was found only between retinol and femoral neck bone mineral density in osteoporotic women. Our study suggests a bone sparing effect of retinol, to which the provitamin A activity of some carotenoids might have contributed.
Maggio
Dario
D
Institute of Gerontology and Geriatrics, University of Perugia, Policlinico Monteluce, Via Brunamonti, 06124 Perugia, Italy. dariomaggio1@tin.it
Polidori
M Cristina
MC
Barabani
Mauro
M
Tufi
Angela
A
Ruggiero
Carmelinda
C
Cecchetti
Roberta
R
Aisa
M Cristina
MC
Stahl
Wilhelm
W
Cherubini
Antonio
A
D000368:Aged; D002338:Carotenoids / Q000097:blood*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D014975:Lutein / Q000097:blood; D010024:Osteoporosis / Q000097:blood* / Q000453:epidemiology; D014801:Vitamin A / Q000097:blood*; D024341:Xanthophylls / Q000097:blood; D065146:Zeaxanthins; D019207:beta Carotene / Q000031:analogs & derivatives / Q000097:blood
D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D014801:Vitamin A; D002338:Carotenoids; D014975:Lutein