Micronutrient requirements of physically active women: what can we learn from iron?

Iron Deficiency Anemia in Pregnancy: Novel Approaches for an Old Problem

Iron needs increase exponentially during pregnancy to meet the increased demands of the fetoplacental unit, to expand maternal erythrocyte mass, and to compensate for iron loss at delivery. In more than 80% of countries in the world, the prevalence of anemia in pregnancy is > 20% and could be considered a major public health problem. The global prevalence of anemia in pregnancy is estimated to be approximately 41.8%. Undiagnosed and untreated iron deficiency anemia (IDA) can have a great impact on maternal and fetal health. Indeed, chronic iron deficiency can affect the general wellbeing of the mother and leads to fatigue and reduced working capacity. Given the significant adverse impact on maternal-fetal outcomes, early recognition and treatment of this clinical condition is fundamental. Therefore, the laboratory assays are recommended from the first trimester to evaluate the iron status. Oral iron supplementation is the first line of treatment in cases of mild anemia. However, considering the numerous gastrointestinal side effects that often lead to poor compliance, other therapeutic strategies should be evaluated. This review aims to provide an overview of the current evidence about the management of IDA in pregnancy and available treatment options.

Does Iron Supplementation Improve Performance in Iron-Deficient Nonanemic Athletes?

CONTEXT

Supplementing iron-deficient nonanemic (IDNA) athletes with iron to improve performance is a trend in endurance sports.

OBJECTIVES

To investigate the benefits of iron on performance, identify a ferritin level cutoff in IDNA athletes, and determine which iron supplementation regimens are most effective.

DATA SOURCES

A search of the PubMed, CINAHL, Embase, ERIC, and Cochrane databases was performed in 2014 including all articles. Citations of pertinent review articles were also searched. In 2017, the search was repeated.

STUDY SELECTION

Inclusion criteria comprised studies of level 1 to 3 evidence, written in the English language, that researched iron supplementation in nonanemic athletes and reported performance outcomes.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

The search terms used included athletic performance, resistance training, athletes, physical endurance, iron, iron deficiency, supplement, non-anemic, low ferritin, ferritin, ferritin blood level, athletes, and sports.

RESULTS

A total of 1884 studies were identified through the initial database search, and 13 were identified through searching references of relevant review articles. A subsequent database search identified 46 studies. Following exclusions, 12 studies with a total of 283 participants were included. Supplementing IDNA athletes with iron improved performance in 6 studies (146 participants) and did not improve performance in the other 6 studies (137 participants). In the 6 studies that showed improved performance with iron supplementation, all used a ferritin level cutoff of ≤20 μg/L for treatment. Additionally, all studies that showed improved performance used oral iron as a supplement.

CONCLUSION

The evidence is equivocal as to whether iron supplementation in IDNA athletes improves athletic performance. Supplementing athletes with ferritin levels <20 μg/L may be more beneficial than supplementing athletes with higher baseline ferritin levels.

Iron deficiency in gynecology and obstetrics: clinical implications and management

Iron deficiency is the commonest cause of anemia during pregnancy; however, its prevalence is highly determined by nutritional and socioeconomic status. Oral iron is the frontline therapy, but is often poorly tolerated. Awareness of the available intravenous formulations is essential for management. Before delivery, risk factors such as multiparity and heavy uterine bleeding increase the prevalence of iron deficiency and should be motivation for early diagnosis and treatment. Neonates born with iron deficiency have a statistically significant increment in both cognitive and behavioral abnormalities that persist after repletion, highlighting the need for heightened awareness of the diagnosis. A smartphone application providing information on nutrition and treatment is provided. New formulations of intravenous iron with carbohydrate cores, which bind elemental iron more tightly, minimize the release of labile free iron to allow complete replacement doses of intravenous iron in 15 to 60 minutes, facilitating and simplifying care.

Treatment of Iron Deficiency in Women

Iron deficiency with and without anaemia is a common cause of morbidity, particularly in women. Iron deficiency is generally the result of an imbalance between iron loss and iron absorption. In women with symptoms suspicious for iron deficiency, it is important to confirm or exclude the suspicion using proper tests. The use of serum ferritin levels is considered the gold standard for diagnosis. Although the ideal ferritin levels are not unknown the current consent is that levels < 40 ng/ml indicate iron deficiency, which needs to be treated in symptomatic patients. However, symptoms can already occur at ferritin levels of < 100 ng/ml and treatment must be adapted to the individual patient. Iron supplementation is only indicated in symptomatic patients diagnosed with iron deficiency whose quality of life is affected. It is important to treat iron deficiency together with its causes or risk factors. For example, blood loss from hypermenorrhea should be reduced. Women also need to receive information about the benefits of an iron-rich diet. If oral treatment with iron supplements is ineffective, parenteral iron administration is recommended.

Physiological and nutritional aspects of post-exercise recovery: specific recommendations for female athletes

Gender-based differences in the physiological response to exercise have been studied extensively for the last four decades, and yet the study of post-exercise, gender-specific recovery has only been developing in more recent years. This review of the literature aims to present the current state of knowledge in this field, focusing on some of the most pertinent aspects of physiological recovery in female athletes and how metabolic, thermoregulatory, or inflammation and repair processes may differ from those observed in male athletes. Scientific investigations on the effect of gender on substrate utilization during exercise have yielded conflicting results. Factors contributing to the lack of agreement between studies include differences in subject dietary or training status, exercise intensity or duration, as well as the variations in ovarian hormone concentrations between different menstrual cycle phases in female subjects, as all are known to affect substrate metabolism during sub-maximal exercise. If greater fatty acid mobilization occurs in females during prolonged exercise compared with males, the inverse is observed during the recovery phase. This could explain why, despite mobilizing lipids to a greater extent than males during exercise, females lose less fat mass than their male counterparts over the course of a physical training programme. Where nutritional strategies are concerned, no difference appears between males and females in their capacity to replenish glycogen stores; optimal timing for carbohydrate intake does not differ between genders, and athletes must consume carbohydrates as soon as possible after exercise in order to maximize glycogen store repletion. While lipid intake should be limited in the immediate post-exercise period in order to favour carbohydrate and protein intake, in the scope of the athlete's general diet, lipid intake should be maintained at an adequate level (30%). This is particularly important for females specializing in long-duration events. With protein balance, it has been shown that a negative nitrogen balance is more often observed in female athletes than in male athletes. It is therefore especially important to ensure that this remains the case during periods of caloric restriction, especially when working with female athletes showing a tendency to limit their caloric intake on a daily basis. In the post-exercise period, females display lower thermolytic capacities than males. Therefore, the use of cooling recovery methods following exercise, such as cold water immersion or the use of a cooling vest, appear particularly beneficial for female athletes. In addition, a greater decrease in arterial blood pressure is observed after exercise in females than in males. Given that the return to homeostasis after a brief intense exercise appears linked to maintaining good venous return, it is conceivable that female athletes would find a greater advantage to active recovery modes than males. This article reviews some of the major gender differences in the metabolic, inflammatory and thermoregulatory response to exercise and its subsequent recovery. Particular attention is given to the identification of which recovery strategies may be the most pertinent to the design of training programmes for athletic females, in order to optimize the physiological adaptations sought for improving performance and maintaining health.

Estimativa da ingestão de ferro e vitamina C em adolescentes no ciclo menstrual

Avaliou-se o nível de ingestão de ferro e vitamina C, em adolescente nas três fases do ciclo menstrual. O consumo alimentar de trinta adolescentes foi analisado pela técnica de registro, durante as fases pré-menstrual, menstrual e pós-menstrual, com a análise de dois registros por indivíduo, em cada fase. A prevalência da ingestão foi feita considerando seis registros alimentares de cada adolescente. Os padrões utilizados como referência foram as Dietary Reference Intakes (DRI)- Estimated Average Requirement (EAR) do Institute of Medicine (IOM), utilizando as abordagens probabilística e ponto de corte, para o ferro e vitamina C, respectivamente, além dos valores do Recommended Dietary Allowances (National Research Council). As adolescentes tinham 15,5 ± 1,7 anos, com idade da menarca de 11,8 ± 1,1 anos e ginecológica de 3,6 ± 1,9 anos. O consumo mediano de ferro foi 10,6 mg/dia e de vitamina C, 77,6 mg/dia. Observou-se pelas DRI-EAR uma prevalência de inadequação para ferro de 22,6% e de vitamina C 34% e pelo National Research Council, de 63,3% e 20%, respectivamente. Apesar da divergência entre os padrões, os resultados apontam risco nutricional para a população estudada. Sugere-se a realização de mais estudos dietéticos, utilizando as DRI-EAR, favorecendo diagnósticos nutricionais com subsequente medidas de intervenção.

Special populations: the female player and the youth player

Females and youth are frequently described as "special" populations in football literature, but together these two populations outnumber male players. What makes females "special" is that they tend to eat less when training and competing than their male counterparts, leading to lower intakes of energy, carbohydrate, and some nutrients. Youth football players are special in regard to energy and nutrient requirements to promote growth and development, as well as to fuel sport. There is limited research on the dietary habits of these two populations, but the available literature suggests that many female and youth players need to increase carbohydrate intake, increase fluid intake, and develop dietary habits to sustain the demands of training and competition.