Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract only
Publication Acceptance Date: 12/1/2001
Publication Date: 3/20/2002
Citation: Hunt, C.D., Vanderpool, R.A. 2002. Dietary boron absorption and excretion kinetics in adult male subject during dietary boron supplementation as determined by stable isotope dilution methodology [abstract]. The Federation of American Societies for Experimental Biology Journal. 16:A995. Interpretive Summary:
Technical Abstract: Plasma boron concentrations do not reflect dietary boron intakes. Therefore a study was designed to examine the kinetics of boron absorption and excretion. For 17d, a male subject (aged 51 yr) consumed a boron- supplemented basal conventional diet (2.0 mg boron/8400 kJ) and collected all urine and feces (analyzed in triplicate). On d 7, a 10B-enriched broccoli meal substituted for breakfast and blood samples (single analyses were collected. The boron isotope ratio (11B/10B; BIR) in plasma changed from a natural abundance (NA) of 3.82 to a postprandial peak enrichment of 3.08 at 4 hr, a 20% increase in 10B, and did not return fully (3.72) to NA after 30.5 hr. The urine BIR peaked within 5 hr (1.34+/-0.01; 67% change in 11B/10 ratio), fell to a transient plateau (3.42) between 31 and 48 hr and did not return to NA until 96 hr (4.06+/-0.04). The fecal BIR (NA=4.00+/- 0.11) reached peak enrichment at 26 hr (2.82+/-0.12), a 29% increase in 10B, and returned to NA at 73 hr. A 60% retention of the dose 10 d postprandial suggests existence of a large exchangeable metabolic pool of boron. Transient stability of the postprandial urine BIR indicates the existence of at least two metabolic pools of boron.