Association of low 25-hydroxyvitamin D concentrations with elevated parathyroid hormone concentrations and low cortical bone density in early pubertal and prepubertal Finnish girls.
BACKGROUND
Very few studies have evaluated both parathyroid hormone (PTH) and 25-hydroxyvitamin D [25(OH)D] and their effects on bone mass in children.


OBJECTIVE
We studied the associations of serum 25(OH)D and intact PTH (iPTH) with bone mineral content (BMC) and bone mineral density (BMD) at different bone sites and the relation between serum 25(OH)D and iPTH in early pubertal and prepubertal Finnish girls.


METHODS
The subjects were 10-12-y-old girls (n = 193) at Tanner stage 1 or 2, who reported a mean (+/- SD) dietary calcium intake of 733 +/- 288 mg/d. 25(OH)D, iPTH, tartrate-resistant acid phosphatase 5b (TRAP 5b), urinary calcium excretion, BMC, areal BMD, and volumetric BMD were assessed by using different methods.


RESULTS
Thirty-two percent of the girls were vitamin D deficient [serum 25(OH)D < or = 25 nmol/L], and 46% of the girls had an insufficient concentration (26-40 nmol/L). iPTH and TRAP 5b concentrations were significantly higher in the deficient group than in the insufficient and sufficient groups [iPTH: 43.9 +/- 15.7 compared with 38.6 +/- 11.2 pg/L (P = 0.049) and 32.7 +/- 12.1 pg/L (P < 0.001), respectively; TRAP 5b: 12.2 +/- 2.9 compared with 11.0 +/- 2.8 U/L (P = 0.009) and 10.9 +/- 1.9 U/L (P = 0.006), respectively]. The girls in the deficient group also had significantly lower cortical volumetric BMD of the distal radius (P < 0.001) and tibia shaft (P = 0.002). High iPTH concentrations were also associated with low total-body apparent mineral density and urinary calcium excretion (P < 0.007).


CONCLUSIONS
Vitamin D-deficient girls have low cortical BMD and high iPTH concentrations, which are consistent with secondary hyperparathyroidism. A low vitamin D concentration accompanied by high bone resorption (TRAP 5b) may limit the accretion of bone mass in young girls.
Cheng
Sulin
S
Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland. cheng@sport.jyu.fi
Tylavsky
Frances
F
Kröger
Heikki
H
Kärkkäinen
Merja
M
Lyytikäinen
Arja
A
Koistinen
Arvo
A
Mahonen
Anitta
A
Alen
Markku
M
Halleen
Jussi
J
Väänänen
Kalervo
K
Lamberg-Allardt
Christel
C
D000135:Acid Phosphatase / Q000097:blood; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D001862:Bone Resorption / Q000175:diagnosis; D002118:Calcium / Q000652:urine; D002136:Calcium, Dietary / Q000008:administration & dosage; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism; D007527:Isoenzymes / Q000097:blood; D010281:Parathyroid Hormone / Q000097:blood*; D011627:Puberty / Q000378:metabolism*; D012621:Seasons; D000071681:Tartrate-Resistant Acid Phosphatase; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood*; D014808:Vitamin D Deficiency / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism*
D015415:Biomarkers; D002136:Calcium, Dietary; D007527:Isoenzymes; D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D002118:Calcium