The Effect of Oral Iron Supplements on Insulin and Glucose Metabolism in Overweight and Obese Women

The Effect of Oral Iron Supplements on Insulin and Glucose Metabolism in Overweight and Obese Women

The study will be a randomized, double-blind, 17-day metabolic intervention trial including 14 days of high-dose or low-dose iron supplementation. A total of 70 overweight or obese (OW/OB) women will be enrolled. Participants will be individually randomized into either the high-iron or low-iron group.

Women in the low-iron group will receive 15 mg of iron as ferrous fumarate daily for 14 days, while women in the high-iron group will receive 195 mg of iron as ferrous sulfate daily for 14 days.

The study consists of three visits in total. On Day 0, a fasting blood sample will be collected and an OGTT will be performed, with additional blood samples collected at 1 hour and 2 hours post-OGTT. The OGTT will be repeated on Day 14, after 14 days of oral iron supplementation, and again on Day 17, four days after oral iron supplementation has been stopped

Inclusion Criteria:

• BMI ≥ 27.5 kg/m2
• serum ferritin <30 μg/L
• hemoglobin ≥ 11 g/dl
• fasting blood glucose < 5.6 mmol/L

Exclusion Criteria:

• intravenous or high dose oral iron in the preceding 2 months
• medical disorders are known to affect iron absorption or metabolism, or T2DM
• cigarette smoking
• recent blood transfusion or major blood loss