Dietary Intake and Thiamin, Iron, and Zinc Status in Elite Nordic Skiers during Different Training Periods

Abstract

This study evaluated how different training periods affect dietary intake and biochemical indices of thiamin, iron, and zinc status in elite Nordic skiers. Subjects.were 17 skiers and 39 controls, ages 18-38 yrs. Dietary data were collected by 7-day food records at 3-month intervals. Coefficient of variation (CV) was used to indicate magnitude of seasonal changes. Energy intake for the year (28 food record days) was 3,802 kcallday (CV 19.1%) in male skiers, 2,754 kcallday (CV 3.7%) in male controls, 2,812 kcallday (CV 9.1%) in female skiers, and 2,013 kcallday (CV 5.9%) in female controls. CVs for thiamin, riboflavin, vitamin C, calcium, magnesium, iron, and zinc intake were 14.1-23.9% (male skiers), 2.9-15.0% (male controls), 4.8-24.5% (female skiers), and 4.3-1 1.5% (female controls). Seasonal changes in energy, carbohydrate, and micronutrient intakes reflected energy expenditure in male endurance athletes particularly. Erythrocyte transketolase activation coefficients and serum ferritin and zinc concentrations did not differ between skiers and controls. Seasonal variations in these biochemical indices of nutritional status were of the same magnitude in skiers and controls, despite large changes in skiers' physical activity.

Micronutrients: interaction between physical activity, intakes and requirements

“…Serum ascorbic acid concentrations were the same 49,54,75 or higher 76 in athletes than in controls. The pooled mean concentrations for serum or plasma ascorbic acid in the above studies were 59 and 56 mmol ⋅ L −1 for athletes (n = 533) and controls (n = 193), respectively.…”

“…The results in this cross-sectional study were adjusted for age, BMI, diet, smoking, serum cholesterol and serum triglycerides. Guilland et al 54 found comparable b-carotene levels in athletes and in controls.…”

“…Keith & Alt 58 found higher E-GRAC in female athletes, but Guilland et al 54 reported levels comparable to the controls. Only Guilland et al 54 reported E-ASTAC values for both athletes and untrained controls; no difference was observed.…”

“…Micronutrient intakes in male athletes are usually above the recommendations and significantly higher than in untrained subjects 49,[51][52][53][54][55][56] . There are, however, occasional reports of marginal vitamin B 6 and E intake in male athletes 54 .…”

“…Micronutrient intakes in male athletes are usually above the recommendations and significantly higher than in untrained subjects 49,[51][52][53][54][55][56] . There are, however, occasional reports of marginal vitamin B 6 and E intake in male athletes 54 . Vitamin intakes in female athletes are typically above the recommendations, but not very much higher than in untrained females 28,30,33,53,[57][58][59][60][61] .…”