Related Experiment Video
Updated: Jun 18, 2026

Quantitating Iron Transport Across the Mouse Placenta In Vivo Using Nonradioactive Iron Isotopes
Published on: May 10, 2022
Iron status in highly active and sedentary young women
Kathleen Woolf1, Megan M St Thomas, Nicole Hahn
1Nutrition Program, Arizona State University, Mesa, AZ 85212, USA.
Abstract:
This study examined iron status and nutrient intake in highly active (n = 28; 20 +/- 2 yr, >/=12 hr purposeful physical activity per week [PPA/wk]) and sedentary (n = 28; 24 +/- 3 yr, =2 hr PPA/wk) women. Participants completed a 7-day weighed-food record (energy, protein, fiber, alcohol, and micronutrients), 7-day pedometer/activity log, and fasting blood draw (hemoglobin, hematocrit, red blood cell indices, C-reactive protein, serum iron, percent transferrin saturation, total iron-binding capacity, ferritin, transferrin receptor [sTfR], and sTfR index). Independent-sample t tests and the Mann-Whitney nonparametric test compared mean values between groups. Lower serum ferritin (p = .01) and mean cell hemoglobin (p < .01) concentrations were found in active than in sedentary women. Higher mean sTfR (p = .01) and sTfR index (p < .01) values were found in the active women. No significant differences were found between groups for the other blood markers. Serum ferritin concentrations (storage iron) indicated iron depletion (Stage I) in 21% of active and 18% of sedentary participants. Nonetheless, 50% of active and 18% of sedentary participants were iron depleted as evidenced by the sTfR index (ratio of functional-to-storage iron). Elevated sTfR concentrations (functional iron) were observed in 25% of active and 3% of sedentary participants. Although the active women reported greater iron (p < .01) but similar heme iron intakes, they had higher mean sTfR, higher sTfR index, and lower serum ferritin concentrations than the sedentary women. Assessment of iron status may require measures not commonly used in routine assessments.
Related Concept Videos
Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
Factors Affecting Erythropoiesis
Several factors influence the erythrocyte production rate, with tissue oxygen level being among the most critical. Intense exercise or high altitudes can cause tissue hypoxia, which triggers the kidneys to release more erythropoietin (EPO) into the bloodstream.
EPO then...
Essential Minerals for Bone Health
Calcium and Phosphorus
Calcium is a critical component of bones, especially in the form of calcium phosphate and calcium carbonate. Since the body cannot make calcium, it must be obtained from the diet. However, calcium cannot be absorbed from the small intestine without...
Microbes and Other Elemental Cycles
