Iron supplementation limits the deleterious effects of repeated blood donation on endurance sport performance but not on iron status.

BACKGROUND: Every day, blood banks worldwide face the challenge of ensuring an adequate blood supply. Iron deficiency is by far the most common cause of deferral of blood donors. The aim of the present study was to determine the effect of iron supplementation after repeated blood donation on iron status and physiological performance. MATERIALS AND METHODS: Forty-four moderately trained and iron-replete subjects were randomly divided into a whole blood donation (n=36) and a placebo donation (n=8) group. One third of the donation group received no iron supplementation, whereas one third received 20 mg iron and one third received 80 mg iron daily for 28 days. The subjects were intended to make three donations 3 months apart, and recovery of endurance capacity, assessed by an incremental maximal cycling test, and haematological parameters was monitored up to 28 days after each donation. RESULTS: Negative effects of repeated blood donation were found for markers of iron storage, markers of functional iron and/or iron metabolism regulation, and physiological markers. Iron supplementation did not affect iron storage but did limit, at the highest dose of 80 mg, the effect of blood donations on functional iron and/or iron metabolism regulation, and at both 20 and 80 mg the negative effects on maximal power output and peak oxygen consumption. DISCUSSION: Iron supplementation limited the deleterious effects of repeated blood donation on endurance sport performance but not on decline in iron status in iron-replete young men. These results underline the importance of iron supplementation to minimise the deleterious effects of blood donation on physiological functions, and the necessity to optimise the supplementation strategy to preserve iron status.

Cranberry versus placebo in the prevention of urinary infections in multiple sclerosis: a multicenter, randomized, placebo-controlled, double-blind trial.

OBJECTIVE: Our aim was to assess the usefulness of cranberry extract in multiple sclerosis (MS) patients suffering from urinary disorders. METHODS: In total, 171 adult MS outpatients with urinary disorders presenting at eight centers were randomized (stratification according to center and use of clean intermittent self-catheterization) to cranberry versus placebo in a 1-year, prospective, double-blind study that was analyzed using a sequential method on an intent-to-treat basis. An independent monitoring board analyzed the results of the analyses each time 40 patients were assessed on the main endpoint. Cranberry extract (36 mg proanthocyanidins per day) or a matching placebo was taken by participants twice daily for 1 year. The primary endpoint was the time to first symptomatic urinary tract infection (UTI), subject to validation by a validation committee. RESULTS: The second sequential analyses allowed us to accept the null hypothesis (no difference between cranberry and placebo). There was no difference in time to first symptomatic UTI distribution across 1 year, with an estimated hazard ratio of 0.99, 95% CI [0.61, 1.60] (p = 0.97). Secondary endpoints and tolerance did not differ between groups. CONCLUSION: Taking cranberry extract versus placebo twice a day did not prevent UTI occurrence in MS patients with urinary disorders. Trial Registration NCT00280592.