Effect of combined iron, zinc, and calcium supplementation on iron, zinc, and calcium status in adolescents: a randomized controlled trial
Micronutrient deficiencies
Current interventions, as of 23/07/2026: Patients will be randomly allocated to one of four groups: 1. Calcium plus vitamin D supplemented group (control group) 2. Calcium plus Fe and vitamin D supplemented group 3. Calcium plus Zn and vitamin D supplemented group 4. Calcium, Fe and Zn and vitamin D supplemented group The calcium (Ca) dose (500 mg) was defined based on 50% of the RDA for this age group. Iron and Zn doses will be established according with the current recommendation for these minerals. Vitamin D dose was 100% EAR. The supplementation period will last for 6 months. _____ Previous interventions as of 18/01/2017: Patients will be randomly allocated to one of four groups: 1. Calcium supplemented group (control group) 2. Calcium plus Fe supplemented group 3. Calcium plus Zn supplemented group 4. Calcium, Fe and Zn supplemented group The calcium (Ca) dose (500 mg) was defined based on 50% of the RDA for this age group. Iron and Zn doses will be established according with the current recommendation for these minerals. The supplementation period will last for 6 months. _____ Previous interventions: Patients will be randomly allocated to one of four groups: 1. Calcium supplemented group (control group) 2. Calcium plus Fe supplemented group 3. Calcium plus Zn supplemented group 4. Calcium, Fe and Zn supplemented group The calcium (Ca) dose (650 mg) was defined based on 50% of the RDA for this age group. Iron and Zn doses will be established according with the current recommendation for these minerals. The supplementation period will last for 12 months.
Current inclusion criteria as of 18/01/2017: 1. Male or female 2. 16 - 18 years old 3. In good health 4. Sexual maturity rating of Tanner stage 5 Previous inclusion criteria: 1. Male or female 2. 16 - 17 years old 3. In good health 4. Sexual maturity rating of Tanner stage 5
1. Use of vitamin supplements containing iron, zinc, calcium, vitamin D during the last 6 months prior the beginning of the trial 2. Known intolerance/allergy to iron, zinc, and calcium supplements 3. Smoking and alcohol abuse or dependence 4. Morbidity (excepting anemia defined as hemoglobin < 120 g/L) 5. Participation in previous studies particularly involving the administration of micronutrient supplements 6. Pregnant or planning a pregnancy during the study period 7. Breastfeeding