ferrous-fumarate and Body-Weight

Earlier studies with ruminants point to a depressant effect of dietary iron on the copper status. To verify this we determined hepatic copper concentrations in dry, non-pregnant goats subjected to a 56 x 56-days cross-over trial with adequate copper rations containing either 269 or 2380 mg iron/kg dry matter. High iron intake reduced the group mean plasma copper (by 18%) and caeruloplasmin activity (by 13%) and produced a significant decrease (27%) in hepatic copper concentrations. Hepatic iron concentrations were raised (by 56%) after feeding the high iron ration. It is concluded that high dietary levels of iron, within the range of their fluctuation in silage and forage, can impair the copper status of ruminants, especially when concurrent intakes of copper are low.

Topics: Animals; Body Weight; Ceruloplasmin; Copper; Cross-Over Studies; Diet; Eating; Female; Ferrous Compounds; Goats; Liver

Factors affecting absorption of physiological doses of vitamin C in man have not been widely studied, partly because few suitable tools exist to distinguish recently absorbed vitamin C from endogenous vitamin. Stable isotope-labelled vitamin C provides such a tool. Fifteen healthy non-smoking subjects aged 26-59 years were studied. Each received 30 mg l-[1-(13)C]ascorbic acid orally on two occasions, 3-4 weeks apart. The ascorbate was given alone or with Fe (100 mg as ferrous fumarate) or with red grape juice, which is rich in polyphenols. Blood was collected at frequent intervals for 1 h, and then each hour for a further 3 h. Total concentration of vitamin C was measured fluorometrically and its (13)C-isotope enrichment was measured by GC-MS after conversion to volatile trimethylsilyl esters. Peak plasma enrichment occurred within 25-50 min. No kinetic variables were significantly altered by the iron fumarate supplement. Grape juice attenuated vitamin C absorption, reaching significance at the 20 min time point. There were weak correlations between isotope enrichment and body weight or endogenous ascorbate concentration. The increment in total plasma ascorbate was smaller if calculated from isotope enrichment than from vitamin C concentration increase. The dilution pool was much larger than the plasma ascorbate pool. Further studies are needed to resolve these paradoxes. Stable isotope-labelled ascorbate is potentially useful for measurement of vitamin C absorption by human subjects.

Topics: Absorption; Administration, Oral; Adult; Ascorbic Acid; Body Weight; Carbon Dioxide; Carbon Isotopes; Citrus paradisi; Dietary Supplements; Female; Ferrous Compounds; Humans; Male; Middle Aged

Serum ferritin concentration of nursing calves was measured by a two-site immunoradiometric assay to assess developmental changes and to evaluate relationships of serum ferritin with iron-related blood characteristics. Serum ferritin concentration of calves was low at birth and elevated slightly at 3 days of age. From 1 wk of age onward, serum ferritin concentration of untreated calves and calves fed only whole milk for 4 wk decreased and remained low throughout the nursing period. This finding almost coincided with hematological characteristics. However, that nearly normal hematological measures and weight gain persisted and that they did not develop any anemic symptom indicate that serum ferritin concentration is more sensitive than other hematological characteristics to iron depletion. However, serum ferritin concentration of calves administered 130 mg of ferrous fumarate (40 mg iron) daily from 3 to 22 days of age or injected with 4 ml of iron-dextran intramuscularly (400 mg iron) at 3 days and 2 wk of age increased sharply just after treatment and persisted high for 2 to 6 wk of age. However, there was large variation between animals for serum ferritin concentration. Thus, it seems likely that serum ferritin concentration is an index for monitoring prelatent iron deficiency of calves.

Topics: Administration, Oral; Aging; Animal Feed; Animals; Blood Proteins; Body Weight; Cattle; Erythrocytes; Female; Ferritins; Ferrous Compounds; Hematocrit; Hemoglobins; Injections, Intramuscular; Iron; Iron-Dextran Complex; Male; Radioimmunoassay