Calcium Intake and Iron Status in Human Studies: A Systematic Review and Dose-Response Meta-Analysis of Randomized Trials and Crossover Studies.

BACKGROUND: The interaction between dietary (and supplementary) divalent ions has been a long-standing issue in human nutrition research. Developing an optimal calcium and iron supplementation recommendation requires detailed knowledge of the potential trade-offs between: 1) the clinical effects of concurrent intake on iron absorption and hematological indices; and 2) the potentially negative effects of separated ingestion on adherence to iron and/or calcium supplements. Human clinical studies have examined the effects of calcium intake on iron status, but there are no meta-analyses or recent reviews summarizing the findings. OBJECTIVES: To synthesize peer-reviewed, human, randomized, and cross-over studies on effects of calcium consumption on iron indices without age, gender, or any other restrictions. METHODS: Weighted mean differences for total, heme, and nonheme iron absorption (%) and serum ferritin (µg/L) were obtained from pooled analysis of the highest daily calcium intake compared to the lowest daily calcium intake. RESULTS: The negative effect of calcium intake was statistically significant in short-term iron absorption studies, but the effect magnitude was low [weighted mean difference (WMD) = -5.57%; 95% CI: -7.09 to -4.04]. The effect of calcium on the iron status was mixed. The inverse dose-response association of calcium intake with the serum ferritin concentration was significant (P value = 0.0004). There was, however, no reduction in the hemoglobin concentration (WMD = 1.22g/L;  95% CI:  0.37-2.07). CONCLUSIONS: The existing body of studies is insufficient to make recommendations with high confidence due to heterogeneity in designs, limitations of ferritin as an iron biomarker, and a lack of intake studies in pregnant women. Prescribing separation of prenatal calcium and iron supplements in free-living individuals is unlikely to affect the anemia burden. There is a need for effectiveness trials comparing the effects of prescribing separated intake to concurrent intake, with functional endpoints as primary outcomes and adherence to each supplement as intermediate outcomes.

Prevalence of Hepatitis C Screening, Testing, and Care Experience Among Young Adults Who Use Prescription Opioids Nonmedically.

PURPOSE: Examine the prevalence of hepatitis C virus (HCV) screening, confirmatory testing, and care experiences among young adult nonmedical prescription opioid (NMPO) users. METHODS: We examined self-reported HCV screening history in a sample of 18- to 29-year-olds reporting past-month NMPO use, and we used modified Poisson regression to identify associated sociodemographic and drug use patterns. RESULTS: Among 196 participants, 154 (78.6%) reported prior HCV screening, among whom 18 (11.7%) reported positive results. Of these, 13 (72.2%) reported receiving a confirmatory test; 12 (66.7%) were referred for specialty HCV care. Screening was associated with injection drug use (adjusted prevalence ratio [APR] = 1.19; 95% confidence interval [CI] = 1.05-1.33) and history of hospitalization for psychiatric illness (APR = 1.23; 95% CI = 1.09-1.39). Younger participants (18-23 years) were less likely to have been screened (APR = .69; 95% CI = .57-.85). CONCLUSION: Among young adult NMPO users, post-HCV screening support and referral to care were inadequate.