The 2011 Report on Dietary Reference Intakes for Calcium and Vitamin D From the Institute of Medicine: What Clinicians Need to Know

Abstract

It is well-recognized that young women with untreated premature ovarian failure (POF) are at increased risk of osteoporosis and bone fracture. Large, randomized trials have demonstrated that hormone replacement therapy with estrogen/progesterone in postmenopausal women can dramatically improve bone mineral density (BMD) and reduce fracture risk; however, there are little data on the effect of hormone replacement in young women with POF. At present, young women with POF are given either combined hormone replacement treatment or physiologic SSR (pSSR) consisting of combined transdermal estradiol and vaginal progesterone replacement regimens.This open-label, randomized controlled crossover pilot trial was designed to determine whether a regimen of pSSR could improve skeletal health among young women with POF caused by a variety of reasons. A total of 34 patients were randomized to receive a 4-week cycle of either pSSR (transdermal estradiol 100 g daily for week 1 and 150 g for weeks 2-4, with progesterone 200 mg twice daily for weeks 3-4) or standard hormone replacement therapy (sHRT) (oral ethinyl estradiol 30 g and norethisterone 1.5 mg daily for weeks 1-3, followed by 7 "pill-free" days for 12 months). Dual-energy x-ray absorptiometry was used to measure BMD at baseline and after each 12-month treatment period. During the study period, blood samples were collected for hormonal measurements and for markers of bone formation (bone alkaline phosphatase and procollagen type I aminoterminal propeptide) and bone resorption (CrossLaps [cross-linked C-terminal telopeptide of type I collagen]) before and after each washout period, and at 3, 6, and 12 months. Of the 34 women, 18 (mean age 27; range, 19-39 years) completed the study. LH (luteinizing hormone) and FSH (follicle-stimulating hormone) were decreased to a similar extent by both pSSR and sHRT. Treatment with pSSR increased the mean baseline lumbar spine BMD z-score by ϩ0.17 (95% confidence interval: ϩ0.07 to ϩ0.27; P ϭ 0.003), whereas there was no significant increase in response to sHRT (ϩ0.07, with a 95% confidence interval: Ϫ0.03 to ϩ0.18; P ϭ 0.2). During pSSR, the increment in lumbar spine BMD z-score was positively associated with estradiol (r ϭ ϩ0.49; P ϭ 0.04) and inversely associated with FSH (r ϭ Ϫ0.65; P ϭ 0.004). Both bone alkaline phosphatase and procollagen type I amino-terminal propeptide were increased significantly by pSSR ( ANOVA P Ͻ 0.001). In contrast, both of these bone formation markers were decreased by sHRT (P Ͻ 0.01). The bone resorption marker, CrossLaps, was suppressed by both regimens (P Ͻ 0.001). GYNECOLOGYVolume 66, Number 6 OBSTETRICAL AND GYNECOLOGICAL SURVEY

Maternal vitamin D status in Type 1 diabetic pregnancy: Impact on neonatal vitamin D status and association with maternal glycaemic control

“…This is particularly important for women at high-risk of deficiency [15]. Recent recommendations from the Institute of Medicine (IOM) advise pregnant and breastfeeding women in the USA and Canada to supplement with 15 mg/day to maintain optimal bone health [28]. Department of Health guidelines in the UK currently recommend pregnant women to supplement with 10 mg/day to protect against vitamin D deficiency [29], but this is disputed by some [30].…”

Associations of serum 25-hydroxycholecalciferol and parathyroid hormone with serum lipids differ by sex and vitamin D status

“…Concentrations of 25(OH)D 3 <25 nmol/l were defined as vitamin D deficiency (22) . Due to the lack of an international consensus on optimal 25(OH)D 3 status, we applied two 25(OH)D 3 cut-off values as adequate (≥50 nmol/l (23) and ≥ 75 nmol/l (24) ). The fasting serum concentrations of TAG, TC and HDL-C (after precipitation with phosphotungstic acid and Mg 2 + ions) were measured using commercial enzymatic methods, such as GPO-PAP for TAG and CHOD-PAP for TC and HDL-C, according to the manufacturer's procedures (Roche Diagnostics GmbH).…”

Controlled trials of vitamin D, causality and type 2 statistical error

“…The US Institute of Medicine and the US Endocrine Society have released separate guidelines for vitamin D requirements. The Institute of Medicine defines 50 nmol/l (20 ng/ml) as the 'sufficient' level of 25(OH)D but this figure was determined by observations of bone health only -that is, calcium absorption, bone mineral density and osteomalacia/rickets (32) . However, the Endocrine Society using a medical model that considered other diseases recommended that a level of 25(OH)D above 75 nmol/l (30 ng/ml) should be attained (33) .…”