TY - JOUR
T1 - Vitamin D insufficiency is prevalent and vitamin D is inversely associated with parathyroid hormone and calcitriol in pregnant adolescents
AU - Young, Bridget E.
AU - McNanley, Thomas J.
AU - Cooper, Elizabeth M.
AU - McIntyre, Allison W.
AU - Witter, Frank
AU - Harris, Z. Leah
AU - O'Brien, Kimberly O.
PY - 2012/1
Y1 - 2012/1
N2 - Few large studies have assessed changes in calcitropic hormones and maternal 25-hydroxyvitamin D (25(OH)D) status across pregnancy, and how this may impact maternal bone turnover and neonatal hormone status. We aimed to identify determinants of 25(OH)D, parathyroid hormone (PTH), and calcitriol across pregnancy in a longitudinal study of 168 pregnant adolescents (≤18 years of age). Maternal 25(OH)D, PTH, and calcitriol were assessed at mid-gestation (∼26 weeks), delivery, and in cord blood. Data were related to measures of maternal anthropometrics, dietary intake, physical activity, and bone turnover markers. Approximately 50% of teens and their infants had serum 25(OH)D a;circ 20 ng/mL; 25(OH)D was lower in African Americans versus whites (p < 0.001). PTH increased across gestation (p < 0.001). Elevated PTH (≥60 pg/mL) was detected in 25% of adolescents at delivery, and was associated with increased concentrations of serum N-telopeptide (NTX) (p=0.028). PTH and calcitriol did not significantly differ across the range of Ca intake consumed (257-3220 mg/d). In the group as a whole, PTH was inversely associated with 25(OH)D in maternal circulation at mid-gestation (p=0.023) and at delivery (p=0.019). However, when the cohort was partitioned by 25(OH)D status, this relationship was only present in those with 25(OH)D≤20 ng/mL, suggestive of a threshold below which 25(OH)D impacts PTH during pregnancy. Mid-gestation 25(OH)D was inversely associated with calcitriol at delivery (p=0.023), irrespective of Ca intake. Neonatal PTH and calcitriol were significantly lower than (p=0.001), but unrelated to maternal concentrations. These findings indicate that maternal 25(OH)D status plays a role in calcitropic hormone regulation in pregnant adolescents.
AB - Few large studies have assessed changes in calcitropic hormones and maternal 25-hydroxyvitamin D (25(OH)D) status across pregnancy, and how this may impact maternal bone turnover and neonatal hormone status. We aimed to identify determinants of 25(OH)D, parathyroid hormone (PTH), and calcitriol across pregnancy in a longitudinal study of 168 pregnant adolescents (≤18 years of age). Maternal 25(OH)D, PTH, and calcitriol were assessed at mid-gestation (∼26 weeks), delivery, and in cord blood. Data were related to measures of maternal anthropometrics, dietary intake, physical activity, and bone turnover markers. Approximately 50% of teens and their infants had serum 25(OH)D a;circ 20 ng/mL; 25(OH)D was lower in African Americans versus whites (p < 0.001). PTH increased across gestation (p < 0.001). Elevated PTH (≥60 pg/mL) was detected in 25% of adolescents at delivery, and was associated with increased concentrations of serum N-telopeptide (NTX) (p=0.028). PTH and calcitriol did not significantly differ across the range of Ca intake consumed (257-3220 mg/d). In the group as a whole, PTH was inversely associated with 25(OH)D in maternal circulation at mid-gestation (p=0.023) and at delivery (p=0.019). However, when the cohort was partitioned by 25(OH)D status, this relationship was only present in those with 25(OH)D≤20 ng/mL, suggestive of a threshold below which 25(OH)D impacts PTH during pregnancy. Mid-gestation 25(OH)D was inversely associated with calcitriol at delivery (p=0.023), irrespective of Ca intake. Neonatal PTH and calcitriol were significantly lower than (p=0.001), but unrelated to maternal concentrations. These findings indicate that maternal 25(OH)D status plays a role in calcitropic hormone regulation in pregnant adolescents.
KW - 1,25-dihydroxyvitamin D
KW - 25-hydroxyvitamin D
KW - Adolescence
KW - Parathyroid hormone
KW - Pregnancy
UR - http://www.scopus.com/inward/record.url?scp=84555195695&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84555195695&partnerID=8YFLogxK
U2 - 10.1002/jbmr.526
DO - 10.1002/jbmr.526
M3 - Article
C2 - 21956833
AN - SCOPUS:84555195695
VL - 27
SP - 177
EP - 186
JO - Journal of Bone and Mineral Research
JF - Journal of Bone and Mineral Research
SN - 0884-0431
IS - 1
ER -