Participants were divided into two groups at each trial site and were assigned to order treatment groups according to a randomization plan of equal block size with a 1:1 allocation ratio to receive either iron supplementation or placebo by an independent researcher. The allocation remained concealed to participants, general instructors, statistical analysts, and principal investigators until the end of the trial. The coding of the groups was revealed to researchers only after all measurements were completed and reported. Participants were instructed to consume the treatment once a day, either before or after meals for four consecutive weeks. The treatments were packaged in the sachet (1.5 g as granules) and were identical in appearance, calorie value (5.7 kcal) taste, and raw materials (dextrin, trehalose, and enzymatically degraded guar gum as stabilizer). The dietary iron sachet contains 3.6 mg of ferric pyrophosphate in granules along with 1.37 g carbohydrates and 1.8 mg sodium (Taiyo Kagaku Cookin Supplement Fe; SunActive Fe®), while the placebo was dextrin (carbohydrates: 1.42 g). The specifications of raw materials and nutrient content of iron and placebo granules supplement were confirmed by an independent accredited laboratory. Compliance was assessed at every visit by counting the number of remaining study product sachets returned by the subjects and using a diary system.
Free full text: Click here
