This randomized, double-blind, active-controlled trial will evaluate the effects of human lactoferrin supplementation combined with low-dose iron on iron status, aerobic performance, and lactate metabolism in exercising women with low ferritin. Approximately 30 healthy, menstruating women aged 18-45 years with serum ferritin \<35 µg/L will be enrolled in an 8-week intervention. Participants will be stratified by baseline ferritin status and randomized to receive 100 mg lactoferrin + 5 mg iron, 300 mg lactoferrin + 5 mg iron, or placebo + 5 mg iron daily.
Primary outcomes include changes in ferritin and hematological parameters. Secondary outcomes include VO₂peak, time to exhaustion, and blood lactate responses during standardized treadmill testing.
This study will determine whether lactoferrin enhances iron homeostasis and improves physiological and performance outcomes in exercising women with low iron stores.
Women, 18 - 45 years of age
No changes in hormonal contraception use in the past 6 months
Has a regular menstrual cycle defined as five out of the past six months
Engaging in ≥5 hours per week of structured endurance exercise (e.g., running, cycling, swimming, rowing) for the past ≥6 months, with ≥3 sessions per week at moderate-to-vigorous intensity (≥70% HRmax or RPE ≥13).
History of any food allergies or intolerances that could impact digestive outcomes and history of irritable bowel syndrome, inflammatory bowel disease (Crohn's, ulcerative colitis, celiac), gastroparesis, chronic constipation or diarrhea requiring medication, or GI surgery
Has any of the following medical conditions: bleeding disorders, active heart or cardiovascular disease, uncontrolled high blood pressure (≥ 140/90 mmHg), renal or hepatic impairment/disease, Type I or II diabetes, any neurologic disease or disorder that may impact cognition or mood, unstable thyroid disease, chronic inflammatory conditions, immune disorders (such as HIV/AIDS), or any medical condition deemed exclusionary by the Principal Investigator (PI)
Acute illness or infection within the past 30 days
History of cancer (except localized skin cancer without metastases) within 5 years prior to screening.