Indicators of Vitamin and Mineral Status in Athletes' Blood: A Review

Abstract

This review examines the hypothesis that vitamin and mineral status in athletes is inadequate for optimal sports performance. The review is based on indicators determined from blood and on studies published since 1980. Most of the studies did not find micronutrient status in athletes to be different from untrained controls. The serum fenitin concentration in females was lower than in males (27 vs. 78 yg . L-I), and the prevalence of low serum ferritin concentration was higher in female athletes than in untrained female controls (37 vs. 23%). Supplementation of water-soluble vitamins and iron was associated with an improvement in the corresponding indicators. Excluding a few studies with mildly anemic subjects, improvements in indicators of micronutrient status were not associated with enhanced athletic performance. Consequently, the levels of indicators of micronutrient status seen in athletes' blood were apparently compatible with optimal physical performance.

Micronutrients: interaction between physical activity, intakes and requirements

“…The pooled mean serum magnesium and zinc concentrations were not different between athletes and untrained controls in studies published between 1980 and 1994 87 . In agreement with the above conclusion, we have also reported approximately similar erythrocyte magnesium levels between male endurance athletes and controls, whereas erythrocyte zinc concentration was even higher in athletes 51 .…”

“…In studies published between 1980 and 1994, the pooled mean results on plasma copper concentration tended to be higher for females than for males: 16.3 and 15.1 mmol ⋅ L −1 for female athletes and controls, and 14.7 and 14.1 mmol ⋅ L −1 for male athletes and controls, respectively 87 . As seen from the above results, the plasma copper concentration tended to be slightly higher in physically active subjects.…”

“…One evident reason for the interest is the well-known associations of blood haemoglobin concentration and physical performance 87 . Iron excretion through sweat, urine and faeces is believed to be increased from normal levels, although contrasting evidence has also been presented (see earlier in this review).…”

“…More recent studies have not brought any new insight into the above view [92][93][94] . However, iron deficiency anaemia, expressed as blood haemoglobin concentration below the lower reference limit, is rare in both physically active people and untrained controls 87,94 .…”

“…In an analytical review 87 , I have pooled the available data on iron status in athletes and controls, published between 1980 and 1994 ( Table 3). The results show slightly lower serum ferritin concentrations in runners, regardless of sex, and also in other female athletes, compared to controls.…”