Serum 25-hydroxyvitamin D levels and bone mineral density in 16-20 years-old girls: lack of association.
OBJECTIVE
Hypovitaminosis D has been shown to be associated with low bone mineral density in middle-aged and elderly women. The aim of this study was to evaluate whether such an association might exist in adolescent and young adult girls, approaching peak bone mass.


METHODS
Cross-sectional study carried out in late winter.


METHODS
Reykjavik area at latitude 64 degrees N.


METHODS
Two-hundred and fifty-nine Icelandic Caucasian girls, aged 16, 18 and 20 years, randomly selected from the registry of Reykjavik.


METHODS
Bone mineral density in lumbar spine, hip, distal forearm and total skeleton was measured with dual-energy X-ray absorptiometry (DEXA) and compared with 25-hydroxyvitamin D levels [25 (OH)D] in serum, measured by radioimmunoassay. Calcium and vitamin-D intake were also assessed by a questionnaire.


RESULTS
18.5% of the girls were below 25 nmol L-1 in serum 25 (OH)D which has been recognized as the lower normal limit for adults. No significant association was found between 25 (OH)D levels and bone mineral density.


CONCLUSIONS
Normal calcium and phosphate concentrations in plasma and normal bone mineral density are maintained in adolescent and young adult girls at lower 25 (OH)D levels than published 'normal' levels for middle-aged and elderly.
Kristinsson
J O
JO
Department of Internal Medicine, Reykjavik Hospital, Iceland.
Valdimarsson
O
O
Sigurdsson
G
G
Franzson
L
L
Olafsson
I
I
Steingrimsdottir
L
L
D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D015519:Bone Density; D002118:Calcium / Q000097:blood; D002136:Calcium, Dietary / Q000008:administration & dosage; D003430:Cross-Sectional Studies; D002149:Energy Intake; D005260:Female; D005838:Genotype; D006801:Humans; D008019:Life Style; D010710:Phosphates / Q000097:blood; D011110:Polymorphism, Genetic; D011863:Radioimmunoassay; D018167:Receptors, Calcitriol / Q000235:genetics; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood
D002136:Calcium, Dietary; D010710:Phosphates; D018167:Receptors, Calcitriol; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium