A Phase 3 interventional study of Concurrent multiple micronutrient and calcium supplementation and Separate multiple micronutrient and calcium supplementation in Anemia, Iron Deficiency, sponsored by Johns Hopkins Bloomberg School of Public Health. Recruiting at 2 sites in 2 countries. Open to female participants aged 15 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-10.
Sponsored by Johns Hopkins Bloomberg School of Public Health · Phase 3, Interventional, and Prevention
The World Health Organization (WHO) currently recommends the pregnant women receive iron-containing supplements and, in settings where calcium intake is low, calcium supplements. Supplements are to be taken at two separate times of the day as calcium may interfere with iron absorption. The goal of this clinical trial is to learn whether taking daily calcium supplements and iron-containing multiple micronutrient supplements together, at the same time, has any negative impact on the hemoglobin or iron status of pregnant women or the woman's infants. Participants will be randomly assigned and counseled to either take the supplements together every morning or to take the multiple micronutrient supplement in the morning and the calcium supplement in the evening. Participants will visit the antenatal clinic monthly and be asked to provide a blood sample in early, mid, and late pregnancy. Researchers will also take blood samples from infants at the time of birth.
Women of reproductive age in low-and-middle-income countries typically consume diets inadequate in many micronutrients. Resulting micronutrient deficiencies are further exacerbated during pregnancy by the increased demands of the developing fetus. Studies show that antenatal micronutrient supplementation can have important benefits for maternal and infant health. While WHO currently recommends daily iron and folic acid supplementation, many countries are transitioning to multiple micronutrient supplementation (MMS) based on evidence of its further benefit in reducing risk of low birth weight, small-for-gestational age births, stillbirths, and preterm delivery. WHO also recommends calcium supplementation for women in settings where calcium intake is low to reduce high blood pressure and prevent preeclampsia and preterm birth.
Women are instructed to take calcium supplements separately from iron-containing supplements to avoid any negative impact of calcium on iron absorption. However, evidence that calcium limits iron absorption is largely from studies of single test meals. Research on the longer-term implications of consuming the two nutrients together for iron status and hemoglobin is limited, particularly in pregnancy. This is an important research question as limiting the number of times per day that a woman needs to take supplements is likely to improve adherence to the regimen. There is also interest in designing a new MMS formulation that includes calcium such that women could take a single tablet daily.
This individually randomized controlled non-inferiority trial will enroll 1,600 women in both Burkina Faso and Pakistan (3,200 in total) to assess the impact of co-administering calcium (500 mg elemental calcium as calcium carbonate) and multiple micronutrient supplements (including 30 mg elemental iron), compared with the currently recommended practice of taking the supplements at two separate times of the day, on hematological and iron status of pregnant women and the women's infants. The sample size is based on a non-inferiority margin of -3.0 g/L, 90% power, a one-sided α=0.025, a standard deviation of 17 g/L for the primary hemoglobin outcome, and 15% loss to follow-up.
Potentially eligible women will be identified through antenatal care visits in Burkina Faso and household visits in Pakistan. For those who consent to screening, research staff will measure hemoglobin and conduct a fetal ultrasound exam. Inclusion and exclusion criteria are provided below. Research staff will obtain written documentation of informed consent.
At enrollment, women will be randomized, and research staff will collect socio-demographic data, take anthropometric and blood pressure measurements, and collect a venous blood sample. Women will receive counseling based on the randomly assigned intervention and be given a supply of study supplements. Research staff will see women monthly at antenatal visits to collect information on adherence by recall and pill count, side effects, signs/symptoms of anemia, and information on any iron treatment that women may have received between visits. Iron treatment prescribed by providers outside of the trial will also be abstracted from medical records. At the mid-pregnancy (20\<24 weeks) and late pregnancy (30\<34 weeks) visits, research staff will take hemoglobin (HemoCue), anthropometric and blood pressure measurements and collect venous blood samples. Women with severe anemia (\<70 g/L) will be referred for treatment. Within 72 hours of birth, research staff will collect a heel prick blood sample from infants. Blood samples will be processed at antenatal clinics and transferred to central laboratories for measurement of hematological parameters, iron status, and inflammation.
600 studies on the registry are indexed under Anemia, Iron-Deficiency; 95 are open to participants now.
This study's planned enrollment of 3,200 is above the median of 100 across 459 interventional studies indexed under Anemia, Iron-Deficiency.
Browse Anemia, Iron-Deficiency studies →Johns Hopkins Bloomberg School of Public Health is the lead sponsor of 371 studies on the registry; 42 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 3 (60%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Daily multiple micronutrient supplement (providing 30 mg iron) taken concurrently with daily calcium supplement (500 mg)
Dietary Supplement: Concurrent multiple micronutrient and calcium supplementation
Daily multiple micronutrient supplement (providing 30 mg iron) taken separately from daily calcium supplement (500 mg)
Dietary Supplement: Separate multiple micronutrient and calcium supplementation
Participants counseled to take United Nations International Multiple Micronutrient Antenatal Preparation (UNIMMAP) multiple micronutrient supplement providing 30 mg elemental iron and calcium supplement providing 500 mg elemental calcium as 1250 mg calcium carbonate together every morning from enrollment through the end of pregnancy
Participants counseled to take United Nations International Multiple Micronutrient Antenatal Preparation (UNIMMAP) multiple micronutrient supplement (MMS) providing 30 mg elemental iron every morning and calcium supplement providing 500 mg elemental calcium as 1250 mg calcium carbonate every evening from enrollment through the end of pregnancy
Hemoglobin concentration of pregnant women
Hemoglobin measured by hematology analyzer
Time frame: 30<34 weeks of gestation
Ferritin concentration
Ferritin (μg/L)
Time frame: 30<34 weeks of gestation
Soluble transferrin receptor (sTfR) concentration
sTfR (mg/L)
Time frame: 30<34 weeks of gestation
Hepcidin concentration
Hepcidin (ng/mL)
Time frame: 30<34 weeks of gestation
Erythropoietin (EPO) concentration
EPO (mIU/mL)
Time frame: 30<34 weeks of gestation
sTfR-Ferritin index
sTfR:log10(ferritin)
Time frame: 30<34 weeks of gestation
Hepcidin-EPO ratio
Hepcidin:EPO
Time frame: 30<34 weeks of gestation
Red blood cell (RBC) count
RBC count
Time frame: 30<34 weeks of gestation
Mean corpuscular volume (MCV)
MCV (fL)
Time frame: 30<34 weeks of gestation
Mean corpuscular hemoglobin (MCH)
MCH (pg)
Time frame: 30<34 weeks of gestation
Mean corpuscular hemoglobin concentration (MCHC)
MCHC (g/dL)
Time frame: 30<34 weeks of gestation
Hemoglobin concentration of infants
Hemoglobin (g/L) measured by HemoCue
Time frame: within 72 hours of birth
Ferritin concentration of infants
Ferritin (μg/L)
Time frame: within 72 hours of birth
Proportion of women with anemia
Hemoglobin \< 110 g/L
Time frame: 30<34 weeks of gestation
Proportion of women with severe anemia (intervention safety)
Hemoglobin \< 70 g/L
Time frame: 20<24 weeks or 30<34 weeks of gestation
Proportion of women with iron deficiency
Ferritin \<15 μg/L (adjusted for inflammation)
Time frame: 30<34 weeks of gestation
Proportion of women with iron-deficient erythropoiesis
Elevated sTfR concentration
Time frame: 30<34 weeks of gestation
Proportion of women with iron deficiency anemia
Concurrent anemia and iron deficiency
Time frame: 30<34 weeks of gestation
Birth weight
Infant's birth weight (g)
Time frame: within 72 hours of birth
Proportion of infants born low birth weight
Infant weight \<2500 g
Time frame: within 72 hours of birth
Gestational age
Gestational age at birth (weeks)
Time frame: within 72 hours of birth
Proportion of infants both preterm
Gestational age \<37 weeks
Time frame: within 72 hours of birth
Weight-for-gestational age Z-score
Calculated using INTERGROWTH-21st standard
Time frame: within 72 hours of birth
Proportion of infants born small for gestational age
\<10th percentile of weight-for-gestational age using INTERGROWTH-21st standard
Time frame: within 72 hours of birth
Proportion of pregnancies ending in miscarriage
Fetal loss \<20 gestational weeks
Time frame: <20 weeks of gestation
Proportion of pregnancies ending in stillbirth
Fetal loss ≥20 gestational weeks
Time frame: ≥20 weeks of gestation
Plan to share: Yes — Individual participant data (IPD) will be available on request by contacting the investigative team.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report
Time frame: IPD will be available after publication of the trial's outcomes
Access criteria: To be agreed upon with investigators
No publications or documents are linked to this record.
Started Aug 2025 (actual). Primary completion is estimated for Apr 2027, 20 months after the start.
Of 48 phase 3 interventional studies under Anemia, Iron-Deficiency, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 14 and three quarters within 41. This study's planned 20 months is below that.
How these figures are worked out, and which studies are left out of them.
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