Iron supplementation in athletes—first do no harm

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Early nutrition and later achievement

Children (227), aged 7–12 years, weighed and recorded all food and drink consumed for seven consecutive days. Each child completed tests of verbal and non-verbal intelligence, and was then randomly allocated to one of two groups after matching for age, sex, IQ and height. In a double-blind trial lasting for 28 d, one group received a vitamin-mineral supplement daily and the other group a placebo. On re-testing, there were no significant differences in performance between the two groups. Furthermore, there were no consistent correlations between test scores and micronutrient intakes based on the weighed records. Thus, we found no evidence that learning ability in a cross-section of British schoolchildren was limited by the quality of their diets.

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Nutrient intakes, vitamin-mineral supplementation, and intelligence in British schoolchildren.

Background Intense physical exercise has been associated with an increase of free radical production. When the body's natural defense systems against free radicals are overwhelmed, oxidative stress increases. Aim of the study This study examined the effects of a vitamin antioxidant supplement, (composed of 600 mg α-tocopherol, 1000 mg ascorbic acid and 32 mg β-carotene) on oxidative, hormonal, and enzymatic exercise stress markers during habitual training activity over 35 days. Methods The plasma concentrations of ascorbic acid, α-tocopherol, β-carotene, testosterone, cortisol and lipid peroxides and the serum activities of lactate dehydrogenase and creatine kinase were measured at four time points: pre-supplementation (PS), pre-training (PT), after training (AT) and 24h after training (24h-AT) in 13 professional basketball players of the first Spanish Basketball League (ACB). Results Antioxidant supplementation led to a significant increase of α-tocopherol and β-carotene from PS to PT. Plasma lipid peroxides decreased about 27.7 % after 35 days of antioxidant treatment. A significant decrease of lactate dehydrogenase serum activity was observed during the 24h recuperation time. During this time the anabolic/catabolic balance increased about 29.8 % in the antioxidant supplemented group, although this increase did not reach statistical significance. Conclusions The results of the present study suggest that supplementation with α-tocopherol, β-carotene and ascorbic acid might partially account for the hormonal and enzymatic stress marker profile observed during habitual training activity of professional basketball players.

Effects of α-tocopherol, β-carotene and ascorbic acid on oxidative, hormonal and enzymatic exercise stress markers in habitual training activity of professional basketball players

H.J. Powers

Papers

Vitamins, iron, and physical work.

Vitamin/mineral supplementation and non-verbal intelligence