Serum 25-hydroxyvitamin D levels in normal subjects: seasonal variations and relationships with parathyroid hormone and osteocalcin.
The measurement of human 25-hydroxyvitamin D (25-OH-D) serum levels has a potential role in evaluating calcium and bone metabolism disorders. To determine normal ranges were studied, cross-sectionally, a healthy population of men and women, aged 18-69 years, over a 12-month period. Changes in 25-OH-D levels for the examined population fitted a mathematical model that demonstrated a highly significant periodic relationship to time. Gender had a significant (p < 0.03) effect on mean 25-OH-D concentration, but age was not significantly correlated with 25-OH-D in either sex. A 95% tolerance band was computed in order to have a time-qualified "range of normality" with circannual periodicity. Interesting periodic variations were seen for the parathyroid hormone (PTH) as well as for osteocalcin (OST). A moderate negative correlation was found between 25-OH-D and PTH in both sexes, with more significant evidence in males. No relationship was observed between 25-OH-D and OST.
Benucci
A
A
Department of Clinical Pathophysiology, University of Florence, Italy.
Tommasi
M
M
Fantappié
B
B
Scardigli
S
S
Ottanelli
S
S
Pratesi
E
E
Romano
S
S
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood*; D010281:Parathyroid Hormone / Q000097:blood*; D012016:Reference Values; D012621:Seasons; D012737:Sex Factors
D006887:Hydroxycholecalciferols; D010281:Parathyroid Hormone; D015675:Osteocalcin