Dietary predictors of concentrations of polychlorinated biphenyls in breast adipose tissue of women living in Ontario, Canada.

The authors evaluated dietary predictors of concentrations of 11 polychlorinated biphenyls (PCBs) in breast adipose tissue from 190 women with benign breast disease who live in Ontario, Canada. Consumption of fish was positively correlated with, and the most consistent dietary predictor of, breast tissue PCB levels. Dietary predictors accounted for < 8% of the variation in breast adipose tissue PCB levels. Age was positively and most strongly associated with tissue PCB levels, perhaps representing long-term dietary intake and the complex interplay of absorption, metabolism, distribution, and excretion.

Is low-dose oral cobalamin enough to normalize cobalamin function in older people?

OBJECTIVES: To investigate whether the use of low-dose oral cobalamin (Cbl) supplements by older persons, as frequently found in multivitamin preparations, affects their Cbl serum concentrations and function, determined by measurements of the serum Cbl-related metabolites methylmalonic acid (MMA), homocysteine (HCYS), and methylcitric acid (MCTR). DESIGN: Cross-sectional study. SETTING: Community. PARTICIPANTS: Two hundred forty-two independent, active, community-living, older adult volunteers recruited from community events and activities for seniors. MEASUREMENTS: We systematically collected data on vitamin supplement intake, diet, medications, and medical and surgical history. Serum was obtained for Cbl, MMA, HCYS, and MCTR, and creatinine and hematological parameters. RESULTS: Serum levels of Cbl were significantly higher in subjects on oral Cbl supplements (2-37.5 microg/day). Similarly, serum levels of the metabolites MMA, HCYS, and MCTR were also lower in subjects on Cbl supplementation. Intake of low-dose oral supplements of Cbl significantly reduced the odds of low Cbl levels or high MMA. The relationship between Cbl supplement dosage and the biochemical parameters was dose dependent. CONCLUSION: Oral Cbl (2-37.5 microg/day) intake by community-dwelling healthy older adults is associated with higher serum levels of Cbl and improved or normalized Cbl function, as indicated by lower concentrations of the metabolites MMA, HCYS, and MCTR. Use of low-dose oral Cbl replacement therapy might be sufficient to prevent Cbl deficiency in a large proportion of this population.