End of winter versus end of summer of vitamin D, parathyroid hormons (PTH) and bone remodeling markers.

GONZALEZ CHAVES M; PONCE G; FAJARDO MA; PELLEGRINI G; OLIVERI B; SOMOZA J; LEONHARDT G; ZENI S

Buenos Aires Argentina

Congreso; Reunión Anual de la Asociación Argentina de Osteología y Metabolismo Mineral; 2005

Asociación Argentina de Osteología y Metabolismo Mineral

23 End of winter versus end of summer levels of vitamin D,parathyroid hormone (PTH) and bone remodeling markers of women from Comodoro Rivadavia M. Gonzales Chaves, G. Ponce, M.A. Fajardo, G. Pellegrini, B. Oliveri, J. Somoza, L. Leonhardt, S.N. Zeni Sec. Osteopatías Me´dicas, Hosp. de Clínicas, UBA, Bromatología, UN Patagonia Although it is frequent in elderly people, young adults may also be at risk of having inadequate vitamin D status. 25hydroxyvitamin D (25HOD) was evaluated in winter and summer to observe  whether changes in vitamin D status havean effect on PTH and bone markers. Healthy women (45-S) (10 pre and 10 postmenopausal) were studied in March and August. In fasting blood 25HOD  (ng/ml) (Diasorin), PTHmm (pg/ml), bone alkaline phosphatase (b-ALP: UI/L), collagen type I N-terminal propeptide (P1NP: ng/ml) and ?-CTX (ng/L) (Elecsys) and in urine CTX (Ag/mmol creatinine) (Crosslaps, Osteometer Bio Tech) were evaluated. Mean T SD winter and summer values of pre and postmenopausal womenrespectively were: 25HOD: 14.7 T 5.6, 26.5 T 10.6*, 12.4 T 4.0, 25.4 T 10.0*; PTH: 46.0 T 9.0, 26.5 T 7.0*, 46.3 T 10.6, 35.2 T 15.0;  b-ALP: 56 T 11, 63 T 10, 63 T 17, 78 T 17#, P1NP: 55.0 T 12.1, 46.2 T 10.6, 59.4 T 16.6, 63.6 T 20.7#-CTX: 210.2 T 49.9, 213.2 T 89.5, 213.2 T 89.5, 356.6 T 156.5#; urinary CTX: 188.9 T 65.6, 146.1 T 48.7, 234.9 T 110.7, 232.4 T 98.5#. (*) P < 0.05: summer vs. winter within the same group, (#) P < 0.05: pre vs. postmenopausal in the same season. Both groups had vitamin D insufficiency in winter and only premenopausal women presented a significant increment in PTH, without an increase in bone markers. Although 25HOD increased approximately 95% in summer, their vitamin D status was still deficient. Only bone markers were significantly different between pre- and postmenopausal summer values. Conclusion: vitamin D insufficiency in winter was still deficient in summer.  Grant from Bs Aires University M033. doi:10.1016/j.bone.2006.02.029