For Physicians. By Physicians.™

ObGFirst: Get guideline notifications, fast. First month free!Click here

EMAS Position Statement: Use of Vitamin D Among Postmenopausal Women

SUMMARY:

EMAS, an international society that promotes health in women and men at midlife and beyond, has produced a position statement targeting the use of vitamin D in postmenopausal women. The literature suggests “an association between vitamin D deficiency and adverse health outcomes in postmenopausal women, although they cannot establish causality.” The document includes an extensive literature review.

‘Vitamin D’ Overview

What is it?

  • Group of lipophilic hormones
  • Regulates calcium homeostasis via kidney, gastrointestinal tract, skeleton and parathyroid
  • Critical for skeletal health but impacts multiple tissues
  • Two major forms
    • Vitamin D2 (ergocalciferol)
    • Vitamin D3 (cholecalciferol)
      • Major source through cutaneous synthesis through exposure to sunlight
      • Small amount from animal diet (fatty fish, eggs and milk)

Measurement

  • Vitamin D status: Measure serum 25-hydroxyvitamin D levels
    • <20 ng/ml (<50 nmol/l): Vitamin D deficiency
    • <10 ng/ml (<25 nmol/l): Severe Vitamin D deficiency

Vitamin D Deficiency and Associated Health Outcomes

  • Skeletal
    • Increased fracture risk
  • Menopausal Symptomatology  
    • Evidence is inconsistent
    • Some studies have demonstrated increased risk
      • Hot flashes | Depression | Sexual dysfunction | Sleep disturbances
  • Cardiac
    • Increased prevalence for CVD risk factors
      • Metabolic syndrome | Type 2 diabetes | Atherogenic dyslipidemia
    • Increased incidence for CVD events
  • Cancer
    • Increased risk for cancers: Colorectal | Lung | Breast
    • Overall and cancer-specific mortality rates are increased in postmenopausal women
    • No evidence for ovarian or other gyn cancers
  • Infections and Inflammation
    • Increased risk for respiratory infection
    • Increased risk for autoimmune disorders

Vitamin D Supplementation Recommendations for Postmenopausal Women

Skeletal Health

  • No vitamin D deficiency or low fracture risk
    • No evidence to support vitamin D supplementation
  • Vitamin D deficiency with osteoporosis and/or high fracture risk (FRAX model)
    • Vitamin D: 2000 to 4000 IU (4000 to 6000 IU in obese patients)
    • Calcium: 1000 to 1200 mg of calcium (dietary or supplements)
    • Encourage Vitamin D and calcium use for minimum 3 to 5 years
    • Check vitamin D levels 3 to 6 months with target above 20 ng/ml (<50 nmol/l)

Menopausal Symptomatology

  • Vitamin D supplementation is not recommended to improve menopausal symptoms

Cardiovascular Disease

  • No effect of vitamin D supplementation on decreasing CVD risk

Cancer

  • No effect of vitamin D supplementation on cancer incidence although some studies identified a small reduction in cancer-related mortality

Infections and Inflammation

  • Vitamin D supplementation may ‘modestly’ decrease the risk for acute respiratory tract infections including COVID-19
  • Concerns regarding study design such as “heterogeneity in design, duration, population and vitamin D dosage among studies must be underscored”

KEY POINTS:

  • Typical daily dose of 1000 to 1200 mg of calcium is not associated with increased risk for cardiovascular disease or nephrolithiasis
  • Studies on vitamin D supplementation have significant limitations due to heterogeneity regarding dose, inclusion of calcium and baseline vitamin D status
  • More research needed to
    • Discriminate between vitamin D replacement and supplementation
    • Determine the need for universal vitamin D screening in postmenopausal women

Learn More – Primary Sources:

EMAS position statement: Vitamin D and menopausal health

Vitamin D Levels: Is There an Association with Livebirth and/or Miscarriage

BACKGROUND AND PURPOSE:

  • Research suggests that serum 25-hydroxyvitamin D (Vitamin D) levels play a role in reproduction
    • Receptors found in important tissues required for normal reproduction
    • Vitamin D may be associated with the immune system
  • Data on this topic limited in humans and generally to IVF/fertility centers
  • Mumford et al. (The Lancet Diabetes & Endocrinology, 2018) examined the association between preconception vitamin D and livebirth/miscarriage among women without fertility issues

METHODS:

  • Secondary analysis of prospective cohort from randomized, double-blind, placebo-controlled trial (RCT)
    • Data from Effects of Aspirin in Gestation and Reproduction (EAGeR) trial
    • Initial trial assessed effects of aspirin on pregnancy loss
  • Participants
    • 18-40 years of age
    • 1 or 2 previous pregnancy losses
  • Vitamin D was measured at
    • Baseline (preconception)
    • 8 weeks of gestation
  • Vitamin D level cut-offs
    • Sufficient concentrations: ≥75 nmol/L
    • Insufficient concentrations: <75 nmol/L
  • Primary outcomes
    • Clinical pregnancy
    • Time to pregnancy (Fecundability)
    • Pregnancy loss
    • Livebirths

RESULTS:

  • 1,191 women were included in the study with data available on preconception 25- hydroxyvitamin D concentrations
    • 47% sufficient
    • 53% insufficient
  • When compared to women with insufficient Vitamin D, women with sufficient preconception Vitamin D were more likely to achieve
    • Clinical pregnancy: adjusted risk ratio (RR) 1.10; 95% CI, 1.01–1.20
    • Livebirth: aRR 1.15; 95% CI, 1.02–1.29
  • Among women who achieved pregnancy, sufficient Vitamin D was associated with reduced risk of pregnancy loss at preconception but not at 8 weeks gestation
    • Preconception: RR per 25 nmol/L 0.88; 95% CI, 0.77–0.99
    • 8 weeks: RR per 25 nmol/L 0.98; 95% CI, 0.95–1.01
  • There was no association between fecundability with sufficient versus those with insufficient preconception VitD levels

CONCLUSION:

  • Sufficient levels of Vitamin D before conception (but not in early pregnancy) are associated with increased likelihood of pregnancy and livebirth
  • Vitamin D levels did not affect time to pregnancy, in keeping with previous research

Learn More – Primary Sources:

Association of preconception serum 25-hydroxyvitamin D concentrations with livebirth and pregnancy loss: a prospective cohort study