Original Article
Kidney International (2003) 63, S44–S48; doi:10.1046/j.1523-1755.63.s85.11.x
Vitamin D status and secondary hyperparathyroidism: The importance of 25-hydroxyvitamin D cut-off levels
Carlos Gómez-Alonso, Manuel L Naves-Díaz, Jose L Fernández-Martín, Jose B Díaz-López, Maria T Fernández-Coto and Jorge B Cannata-Andía
Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación; and Servicio de Bioquímica, Hospital Central de Asturias, Universidad de Oviedo, Spain
Correspondence: Carlos Gómez-Alonso, Servicio de Metabolismo Oseo y Mineral, Instituto Reina Sofía de Investigación, Hospital Central de Asturias, C/Julián Clavería s/n, 33006 Oviedo, Spain. E-mail: cgomez@hca.es
Abstract
Vitamin D status and secondary hyperparathyroidism: The importance of 25-hydroxyvitamin D cut-off levels.
Background
Serum 25-hydroxyvitamin D is the best indicator of vitamin D status. However, some controversy remains regarding "normal" and "abnormal" values. This study's aim was to assess vitamin D status and prevalence of secondary hyperparathyroidism.
Methods
A random sample of 326 subjects (164 women and 162 men, aged 68 
9; range, 54 to 89) participating in the European Vertebral Osteoporosis Study (EVOS) was used to assess vitamin D status and secondary hyperparathyroidism. Only those subjects who had never received any kind of treatment for osteoporosis were included in this analysis.
Results
Serum 25-hydroxyvitamin D levels were "deficient" (<10 ng/mL) in 27% of subjects, "borderline" (10–18 ng/mL) in 40% of subjects, and "normal" (>18 ng/mL) in 33% of subjects. The prevalence of secondary hyperparathyroidism (PTH>65 pg/mL) according to 25-hydroxyvitamin D levels was 33% (<10 ng/mL), 16% (10–18 ng/mL), and 12% (>18 ng/mL), respectively. There were no cases of secondary hyperparathyroidism with 25-hydroxyvitamin D levels>40ng/mL. The independent predictors for PTH were 25-hydroxyvitamin D and serum creatinine in both sexes, but age was a predictor only in men.
Conclusion
These remarkable findings demonstrate the importance of maintaining higher 25-hydroxyvitamin D levels to avoid stimulation of the parathyroid gland.
Keywords:
calcifediol, calcitriol, vitamin D deficiency, parathyroid hormone
