Postpartum vitamin D insufficiency and secondary hyperparathyroidism in healthy Danish women

Abstract

Objective: To examine vitamin D status and parathyroid function in normal Danish women postpartum. Design: Three cross-sectional measures during follow-up of 89 women postpartum. Subjects and intervention:We assessed vitamin D status by measuring plasma 25-hydroxyvitamin D (P-25OHD) and the degree of secondary hyperparathyroidism by measuring plasma parathyroid hormone (P-PTH) in 89 Caucasian women at three consecutive visits: (mean (range)) 23 (10-37) days (spring), 117 (95-140) days (late summer) and 274 (254-323) days (winter) postpartum. Results: P-25OHD showed seasonal variations with higher values in late summer than in the other periods (Po0.001). At the first visit, 65% received vitamin D supplements. At the following visits, almost 50% were supplemented. Vitamin D insufficiency (P-25OHDo50 nmol/l) occurred more often during winter (28%) than in spring (14%) (Fisher's exact test, P ¼ 0.02) or late summer (7%) (P ¼ 0.0001). Irrespective of season, vitamin D insufficiency occurred most frequent in women who did not take vitamin D supplements (Fisher's exact test, Po0.02). Frank vitamin D deficiency (P-25OHDo25 nmol/l) was observed during winter in 6%. At all three periods, P-25OHD correlated inversely with P-PTH indicating secondary hyperparathyroidism at deficient vitamin D status. During spring, late summer and winter three, one and four females, respectively, had elevated plasma PTH. Conclusion: Vitamin D insufficiency with secondary hyperparathyroidism is a frequent finding in healthy Danish women postpartum and especially during winter. Vitamin D supplements reduced the risk of vitamin D insufficiency, especially during winter. Our results support the importance of increased alertness regarding information of pregnant and lactating women about vitamin D supplements. Furthermore, it has to be studied whether the present recommendations of an intake of 5-10 mg vitamin D/day are sufficient, especially during winter months.

Plasma 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and parathyroid hormone in familial hypocalciuric hypercalcemia and primary hyperparathyroidism

“…This is in accordance with the findings in normal Danish individuals (33), in Danish lactating women (34), and in Danish patients with PHPT (6). In the latter study, plasma 25OHD covariated with monthly sun hours and satellite-based estimation of monthly UV exposure.…”

“…The usually observed inverse hyperbolic relationship between 25OHD and plasma PTH (33,34,39,40) could not be retrieved in the present FHH population in contrast to the findings in the PHPT population. Other studies support that PTH varies inversely with vitamin D status in PHPT patients (6,8).…”

A Cross-Sectional Study of Postpartum Changes in Bone Status in Indian Mothers

“…Our study also reports higher prevalence of vitamin D deficiency in Indian postpartum women in line with other studies [31][32][33][34]. In a Danish study, Møller et al also reported higher prevalence of vitamin D deficiency along with secondary hyperparathyroidism around 1 year postpartum, although the incidence was lower than that in our study population [35].…”

Maternal and infant vitamin D status during the first 9 months of infant life—a cohort study

“…20,21 Accordingly, pregnant and breastfeeding women in Scandinavia are recommended to use a daily supplement of 10 mg (400 IU) of vitamin D. 22,23 Furthermore, it is recommended that children aged 2 weeks to 2 years receive a daily supplement of 10 mg of vitamin D. 22,23 Whether these recommendations are adequate is still uncertain, as recent studies have suggested that the supplement should be increased to 25-100 mg per day. 5,20,[24][25][26][27][28] In a population-based cohort study, we aimed at the following: (1) to investigate the prevalence of vitamin D deficiency and insufficiency in Caucasian infants and their mothers at birth and 4 and 9 months after birth; (2) to identify determinants of maternal and infant vitamin D status and to appraise associations between vitamin D status in the newborn children and their mothers; (3) to investigate interactions between plasma 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) levels; and (4) to assess the influence of plasma 25OHD and PTH levels on infant body weight and growth rates.…”

“…1,2 Pregnant and lactating women and their newborn infants are at a high risk of vitamin D deficiency. [3][4][5][6][7][8][9][10][11][12] Vitamin D is involved in skeletal homeostasis during pregnancy. 13,14 Severe vitamin D deficiency with profound hypocalcemia may lead to seizures in neonates, and has also been associated with low birth weight, prenatal death, preeclampsia and an increased risk of primary cesarean section.…”