Highlights
Abstract
Keywords
Abbreviations
1. Introduction
2. Iron
3. Antioxidants
4. Vitamin D
5. Calcium
6. Discussion/conclusion
CRediT authorship contribution statement
Declaration of competing interest
References
Abstract
Optimising nutrition intake is a key component for supporting athletic performance and supporting adaption to training. Athletes often use micronutrient supplements in order to correct vitamin and mineral deficiencies, improve immune function, enhance recovery and or to optimise their performance. The aim of this review was to investigate the recent literature regarding micronutrients (specifically iron, vitamin C, vitamin E, vitamin D, calcium) and their effects on physical performance. Over the past ten years, several studies have investigated the impacts of these micronutrients on aspects of athletic performance, and several reviews have aimed to provide an overview of current use and effectiveness. Currently the balance of the literature suggests that micronutrient supplementation in well-nourished athletes does not enhance physical performance. Excessive intake of dietary supplements may impair the body's physiological responses to exercise that supports adaptation to training stress. In some cases, micronutrient supplementation is warranted, for example, with a diagnosed deficiency, when energy intake is compromised, or when training and competing at altitude, however these micronutrients should be prescribed by a medical professional. Athletes are encouraged to obtain adequate micronutrients from a wellbalanced and varied dietary intake.
1. Introduction The foundations of sport performance are training and nutrition/diet of the athlete, with nutritional strategies providing a supportive role in enhancing training adaption (Stellingwerff et al., 2019). In line with the evolution of methods to optimise training through various training prescriptions, there has been a concurrent evolution in nutrition strategies for athletes. Current nutritional consensus statements promote the periodisation of nutritional intake to optimise the adaptation from the training programme prescribed to the athlete (Stellingwerff et al., 2019). The theory of nutritional periodisation is planned energetic and macronutrient strategies to target the individual exercise sessions and overall training programme to aid in obtaining long term performance gains in athletes (Jeukendrup, 2017). Strategies of nutritional periodisation include manipulating carbohydrate and fat intake to upregulate key signalling pathways in the skeletal muscle and promote mitochondrial biogenesis, angiogenesis and increased lipid oxidation (Hansen et al., 2005; Hulston et al., 2010; Morton et al., 2009) or optimising protein intake to support hypertrophic responses in skeletal muscle (Stellingwerff et al., 2019). However, numerous metabolic processes and reactions involved in energy extraction from macronutrients, oxygen delivery and transfer, tissue repair, and growth and development are dependent on essential vitamins and minerals (Volpe, 2007).
Micronutrients are essential for life and include; vitamins which are organic compounds that support health, growth and reproduction and are needed in small amounts to prevent clinical deficiencies and declines in health (Fogelholm, 2015). A key feature of most vitamins is that the human body is unable to synthesise them (Fogelholm, 2015), therefore they must be obtained from dietary intake. Vitamins are classified based on their in vivo solubility, with A, D, E and K classified as fat-soluble and vitamins B and C classified as water soluble (Fogelholm, 2015). Minerals are inorganic substances that support physiological functioning (Fogelholm, 2015). The daily physiological requirements determine the mineral classifications, hence ~100 mg⋅day− 1 of macrominerals (sodium, potassium, calcium, phosphorus and magnesium) and ~20 mg⋅day− 1 of trace elements (iron, zinc, copper, chromium and selenium) are required by healthy individuals (Fogelholm, 2015).