Trial Outcomes & Findings for Daily vs. Every Other Day Oral Iron Supplementation in Patients With Absolute Iron Deficiency Anemia (NCT NCT03725384)

NCT ID: NCT03725384

Last Updated: 2025-02-03

Results Overview

Enrollment in the trial will be defined as documentation of informed consent for patients approached. The primary outcome of this study is the feasibility of enrolling 52 participants in the trial over a 2-year period. Eligibility based on lab criteria was determined after consent.

• Recruitment status: COMPLETED
• Study phase: PHASE3
• Target enrollment: 51 participants
• Primary outcome timeframe: 2 years
• Results posted on: 2025-02-03

Participant Flow

Participant milestones

Measure	Iron Daily Ferrous sulfate (iron) 300mg tablet and vitamin C 500mg tablet taken by mouth every day for 12 weeks	Iron Every Other Day Ferrous sulfate (iron) 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks
Overall Study STARTED	24	27
Overall Study COMPLETED	21	25
Overall Study NOT COMPLETED	3	2

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Measure	Iron Daily n=24 Participants Ferrous sulfate (iron) 300mg tablet and vitamin C 500mg tablet taken by mouth every day for 12 weeks	Iron Every Other Day n=27 Participants Ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total n=51 Participants Total of all reporting groups
History of bleeding in the past 2 months	16 Participants n=24 Participants	23 Participants n=27 Participants	39 Participants n=51 Participants
Menstrual bleeding, pictorial blood assessment chart >/= 100	7 Participants n=24 Participants	16 Participants n=27 Participants	23 Participants n=51 Participants
History of rheumatological disorders	4 Participants n=24 Participants	3 Participants n=27 Participants	7 Participants n=51 Participants
Medication history Ranitidine	0 Participants n=24 Participants	1 Participants n=27 Participants	1 Participants n=51 Participants
Medication history Proton pump inhibitor	1 Participants n=24 Participants	0 Participants n=27 Participants	1 Participants n=51 Participants
Oral iron use in the past year	13 Participants n=24 Participants	13 Participants n=27 Participants	26 Participants n=51 Participants
IV iron use in the past year	1 Participants n=24 Participants	5 Participants n=27 Participants	6 Participants n=51 Participants
Baseline haemoglobin	110 g/L STANDARD_DEVIATION 13 • n=24 Participants	110 g/L STANDARD_DEVIATION 10 • n=27 Participants	110 g/L STANDARD_DEVIATION 11 • n=51 Participants
Baseline haemoglobin <100 g/L	3 Participants n=24 Participants	3 Participants n=27 Participants	6 Participants n=51 Participants
Baseline mean corpuscular volume (MCV)	80.0 fL STANDARD_DEVIATION 8.2 • n=24 Participants	80.6 fL STANDARD_DEVIATION 8.0 • n=27 Participants	80.3 fL STANDARD_DEVIATION 8.1 • n=51 Participants
Age, Continuous	47.2 years STANDARD_DEVIATION 18.1 • n=24 Participants	44.4 years STANDARD_DEVIATION 17.1 • n=27 Participants	45.7 years STANDARD_DEVIATION 17.5 • n=51 Participants
Sex: Female, Male Female	20 Participants n=24 Participants	21 Participants n=27 Participants	41 Participants n=51 Participants
Sex: Female, Male Male	4 Participants n=24 Participants	6 Participants n=27 Participants	10 Participants n=51 Participants
Race and Ethnicity Not Collected	—	—	0 Participants Race and Ethnicity were not collected from any participant.
Region of Enrollment Canada	24 participants n=24 Participants	27 participants n=27 Participants	51 participants n=51 Participants
Body Mass Index	25.9 kg/m^2 STANDARD_DEVIATION 6.7 • n=24 Participants	27.0 kg/m^2 STANDARD_DEVIATION 7.0 • n=27 Participants	26.5 kg/m^2 STANDARD_DEVIATION 6.8 • n=51 Participants
Reason for iron deficient anemia (IDA) diagnosis Menorrhagia	11 Participants n=24 Participants	17 Participants n=27 Participants	28 Participants n=51 Participants
Reason for iron deficient anemia (IDA) diagnosis Blood donation	6 Participants n=24 Participants	3 Participants n=27 Participants	9 Participants n=51 Participants
Reason for iron deficient anemia (IDA) diagnosis Gastrointestinal	4 Participants n=24 Participants	4 Participants n=27 Participants	8 Participants n=51 Participants
Reason for iron deficient anemia (IDA) diagnosis Other	3 Participants n=24 Participants	3 Participants n=27 Participants	6 Participants n=51 Participants
Baseline reticulocyte count	48 x10^9 cells/L n=24 Participants	47 x10^9 cells/L n=27 Participants	48 x10^9 cells/L n=51 Participants
Baseline ferritin	9 mu grams/L n=24 Participants	9 mu grams/L n=27 Participants	9 mu grams/L n=51 Participants
Baseline serum iron	8 mu mol/L n=24 Participants	5 mu mol/L n=27 Participants	7 mu mol/L n=51 Participants
Baseline C reactive protein	0.9 mg/L n=24 Participants	1.0 mg/L n=27 Participants	0.9 mg/L n=51 Participants
Baseline C reactive protein >/=5 mg/L	1 Participants n=24 Participants	4 Participants n=27 Participants	5 Participants n=51 Participants
Baseline creatinine	0.83 mg/dL n=24 Participants	0.70 mg/dL n=27 Participants	0.78 mg/dL n=51 Participants

PRIMARY outcome

Timeframe: 2 years

Enrollment in the trial will be defined as documentation of informed consent for patients approached. The primary outcome of this study is the feasibility of enrolling 52 participants in the trial over a 2-year period. Eligibility based on lab criteria was determined after consent.

Outcome measures

Measure	Total Number Screened for Eligbility n=216 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms Total number of patients that were allocated to one of the study arms
Feasibility of Enrolling Patients in the Trial	85 participants	—	—

SECONDARY outcome

Timeframe: 2 years

Proportion of eligible patients after initial inclusion/exclusion screening that consent to participating in the study. Eligibility based on lab criteria was determined after consent.

Outcome measures

Measure	Total Number Screened for Eligbility n=216 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms Total number of patients that were allocated to one of the study arms
Proportion of Eligible Participants Consenting	0.39 Proportion of participants	—	—

SECONDARY outcome

Timeframe: 2 years

Proportion of patients who signed informed consent and received the allocated treatment they were randomly assigned to.

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms n=51 Participants Total number of patients that were allocated to one of the study arms
Proportion of Patients Receiving the Allocated Treatment	0.96 Proportion of participants	1 Proportion of participants	0.98 Proportion of participants

SECONDARY outcome

Timeframe: 2 years

Proportion of treated patients who completed both 4 week and 12 week laboratory tests

Outcome measures

Measure	Total Number Screened for Eligbility n=23 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms n=50 Participants Total number of patients that were allocated to one of the study arms
Proportion of Patients Completing Laboratory Tests	0.91 Proportion of participants	0.81 Proportion of participants	0.86 Proportion of participants

SECONDARY outcome

Timeframe: 2 years

Proportion of treated patients completing 4 week, 8 week and 12 week side effect questionnaire

Outcome measures

Measure	Total Number Screened for Eligbility n=23 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms Total number of patients that were allocated to one of the study arms
Proportion of Treated Patients Completing Side Effect Questionnaire at Week 4, 8 and 12	0.91 Proportion of participants	0.85 Proportion of participants	—

SECONDARY outcome

Timeframe: 2 years

Proportion of patients who received treatment and completed 4 week, 8 week and 12 week FACIT-fatigue scale

Outcome measures

Measure	Total Number Screened for Eligbility n=23 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms Total number of patients that were allocated to one of the study arms
Proportion of Patients Completing FACIT-fatigue Scale	0.91 Proportion of participants	0.89 Proportion of participants	—

SECONDARY outcome

Timeframe: 2 years

Adherence was measured by the proportion of treated patients who took at least 90% of their prescribed doses

Outcome measures

Measure	Total Number Screened for Eligbility n=23 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms Total number of patients that were allocated to one of the study arms
Adherence to Treatment	0.78 Proportion of participants	0.82 Proportion of participants	—

SECONDARY outcome

Timeframe: 2 years

Proportion of treated patients requiring a step down in therapy by Week 4 and Week 12 (same proportions at both time points).

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms Total number of patients that were allocated to one of the study arms
Proportion of Treated Patients Requiring a Step Down in Therapy	0.13 Proportion of participants	0 Proportion of participants	—

SECONDARY outcome

Timeframe: 12 weeks

Hemoglobin increment at 4 and 12 weeks is defined as the 4 or 12 week hemoglobin value minus the baseline hemoglobin value

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms n=51 Participants Total number of patients that were allocated to one of the study arms
Hemoglobin Increment Hemoglobin at baseline	110 g/L Standard Deviation 13	110 g/L Standard Deviation 10	110 g/L Standard Deviation 11
Hemoglobin Increment Hemoglobin at 4 weeks	122 g/L Standard Deviation 7	119 g/L Standard Deviation 10	121 g/L Standard Deviation 9
Hemoglobin Increment Hemoglobin at 12 weeks	131 g/L Standard Deviation 9	126 g/L Standard Deviation 8	129 g/L Standard Deviation 9

SECONDARY outcome

Timeframe: 2 years

Proportion with complete hemoglobin response defined as hemoglobin greater than or equal to 120 g/L in women; and 130 g/L in men at 4 weeks and 12 weeks

Outcome measures

Measure	Total Number Screened for Eligbility n=27 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=24 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms Total number of patients that were allocated to one of the study arms
Proportion With Complete Hemoglobin Response	0.59 Proportion of participants	0.75 Proportion of participants	—

SECONDARY outcome

Timeframe: 12 weeks

Change in reticulocyte count at 4 and 12 weeks defined as the 4 or 12 week reticulocyte count minus the baseline reticulocyte count

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms n=51 Participants Total number of patients that were allocated to one of the study arms
Reticulocyte Count Baseline reticulocyte count	48 x10^9 cells/ L Interval 39.0 to 54.0	47 x10^9 cells/ L Interval 41.0 to 65.0	48 x10^9 cells/ L Interval 41.0 to 62.0
Reticulocyte Count Week 4 reticulocyte count	61 x10^9 cells/ L Interval 45.0 to 71.0	65 x10^9 cells/ L Interval 48.0 to 79.0	64 x10^9 cells/ L Interval 47.0 to 78.0
Reticulocyte Count Week 12 reticulocyte count	47 x10^9 cells/ L Interval 39.0 to 56.0	52 x10^9 cells/ L Interval 42.0 to 62.0	47 x10^9 cells/ L Interval 41.0 to 61.0

SECONDARY outcome

Timeframe: 12 weeks

Change in ferritin at 12 weeks, defined as the value at 12 weeks minus the baseline value.

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms n=51 Participants Total number of patients that were allocated to one of the study arms
Change in Ferritin at 12 Weeks Baseline ferritin	9 mcg/L Interval 5.0 to 17.0	9 mcg/L Interval 4.0 to 11.0	9 mcg/L Interval 4.0 to 14.0
Change in Ferritin at 12 Weeks Week 12 ferritin	30 mcg/L Interval 23.0 to 39.0	23 mcg/L Interval 20.0 to 34.0	27 mcg/L Interval 20.0 to 36.0

SECONDARY outcome

Timeframe: 12 weeks

Change in serum iron at 12 weeks defined as the value at 12 weeks minus the baseline value

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms n=51 Participants Total number of patients that were allocated to one of the study arms
Change in Serum Iron at 12 Weeks Baseline serum iron	8 micro mol/L Interval 5.0 to 11.0	5 micro mol/L Interval 4.0 to 9.0	7 micro mol/L Interval 5.0 to 11.0
Change in Serum Iron at 12 Weeks Week 12 serum iron	17 micro mol/L Interval 16.0 to 25.0	12 micro mol/L Interval 9.0 to 16.0	16 micro mol/L Interval 11.0 to 19.0

SECONDARY outcome

Timeframe: 12 weeks

Change in transferrin saturation (TSAT) at 12 weeks defined as the value at 12 weeks minus the baseline value. Interquartile range represents Q1 (25th percentile) to Q3 (75th percentile)

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms n=51 Participants Total number of patients that were allocated to one of the study arms
Change in TSAT at 12 Weeks Baseline TSAT	11 percentile Interval 6.0 to 17.0	7 percentile Interval 6.0 to 10.0	9 percentile Interval 4.0 to 14.0
Change in TSAT at 12 Weeks Week 12 TSAT	26 percentile Interval 21.0 to 42.0	18 percentile Interval 14.0 to 27.0	23 percentile Interval 16.0 to 31.0

SECONDARY outcome

Timeframe: 12 weeks

Quality of life (FACIT-fatigue scale) at 4, 8 and 12 weeks. Functional Assessment of Chronic Illness Therapy (FACIT) - fatigue scale.

On this scale, lower scores indicate better symptoms and higher scores represent worse symptoms. The FACIT-fatigue scale has a range from 0 to 52.

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms n=51 Participants Total number of patients that were allocated to one of the study arms
FACIT-fatigue Score at 4, 8 and 12 Weeks Week 4 FACIT-fatigue score	23.9 score on a scale Standard Deviation 9.8	26.3 score on a scale Standard Deviation 9.7	25.2 score on a scale Standard Deviation 9.7
FACIT-fatigue Score at 4, 8 and 12 Weeks Week 8 FACIT-fatigue score	21.5 score on a scale Standard Deviation 8.5	24.9 score on a scale Standard Deviation 11.4	23.4 score on a scale Standard Deviation 10.2
FACIT-fatigue Score at 4, 8 and 12 Weeks Week 12 FACIT-fatigue score	20.1 score on a scale Standard Deviation 8.5	21.9 score on a scale Standard Deviation 9.9	21.0 score on a scale Standard Deviation 9.3

SECONDARY outcome

Timeframe: 12 weeks

Proportion of patients with side effects at 4, 8 and 12 weeks, as determined by the oral iron side effect questionnaire

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms n=51 Participants Total number of patients that were allocated to one of the study arms
Proportion of Patients With Side Effects at 4, 8 and 12 Weeks Week 4	0.38 Proportion of participants	0.56 Proportion of participants	0.47 Proportion of participants
Proportion of Patients With Side Effects at 4, 8 and 12 Weeks Week 8	0.33 Proportion of participants	0.48 Proportion of participants	0.41 Proportion of participants
Proportion of Patients With Side Effects at 4, 8 and 12 Weeks Week 12	0.33 Proportion of participants	0.44 Proportion of participants	0.39 Proportion of participants

SECONDARY outcome

Timeframe: 12 weeks

Number of patients who discontinued oral iron therapy due to side effects by week 12.

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms n=51 Participants Total number of patients that were allocated to one of the study arms
Proportion of Patients Who Stopped Oral Iron Due to Side Effects	0 Proportion of participants	0 Proportion of participants	0 Proportion of participants

SECONDARY outcome

Timeframe: 2 years

Need for escalation in therapy (increase in oral iron regimen from every other day to daily, need for intravenous iron, need for transfusion, visit to emergency department related to anemia) assessed at 12 weeks

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms Total number of patients that were allocated to one of the study arms
Number of Patients in Need of Escalation Therapy	0 Participants	0 Participants	—

SECONDARY outcome

Timeframe: 2 years

Proportion of patients with a drop in hemoglobin of 10 g/L or more at weeks 4 and 12

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms Total number of patients that were allocated to one of the study arms
Proportion of Patients With a Drop in Hemoglobin at Weeks 4 and 12	0 Proportion of participants	0 Proportion of participants	—

SECONDARY outcome

Timeframe: 4 Weeks

Proportion of patients with each type of adverse event at week 4.

Outcome measures

Measure	Total Number Screened for Eligbility n=24 Participants Total number of participants screened for eligibility to be included in the study	Total Number Allocated to Iron Every Other Day n=27 Participants Total number of patients allocated to receive ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks	Total Number of Patients Allocated to Study Arms n=51 Participants Total number of patients that were allocated to one of the study arms
Types of Adverse Effects at 4 Weeks Constipation	0.25 Proportion of participants	0.22 Proportion of participants	0.24 Proportion of participants
Types of Adverse Effects at 4 Weeks Nausea	0.17 Proportion of participants	0.26 Proportion of participants	0.22 Proportion of participants
Types of Adverse Effects at 4 Weeks Headache	0.17 Proportion of participants	0.26 Proportion of participants	0.22 Proportion of participants
Types of Adverse Effects at 4 Weeks Breathlessness	0.17 Proportion of participants	0.26 Proportion of participants	0.22 Proportion of participants
Types of Adverse Effects at 4 Weeks Heartburn	0.08 Proportion of participants	0.30 Proportion of participants	0.20 Proportion of participants
Types of Adverse Effects at 4 Weeks Abdominal pain	0.08 Proportion of participants	0.19 Proportion of participants	0.14 Proportion of participants
Types of Adverse Effects at 4 Weeks Diarrhea	0.08 Proportion of participants	0.19 Proportion of participants	0.14 Proportion of participants
Types of Adverse Effects at 4 Weeks Vomiting	0.04 Proportion of participants	0.11 Proportion of participants	0.08 Proportion of participants
Types of Adverse Effects at 4 Weeks Other	0.21 Proportion of participants	0.22 Proportion of participants	0.22 Proportion of participants

Adverse Events

Ferrous Sulfate and Vitamin C Every Other Day

Serious events: 0 serious events

Other events: 15 other events

Deaths: 0 deaths

Ferrous Sulfate and Vitamin C Daily

Serious events: 0 serious events

Other events: 9 other events

Deaths: 0 deaths

Total/All Participants

Serious events: 0 serious events

Other events: 24 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Measure	Ferrous Sulfate and Vitamin C Every Other Day n=27 participants at risk Ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every other day for 12 weeks Ferrous Sulfate 300Mg Tablet: oral dose of Ferrous Sulfate (300 mg) every day versus every other day along with vitamin C Vitamin C 500Mg tablet: Vitamin C 500 Mg tablet every day versus every other day along with ferrous sulfate	Ferrous Sulfate and Vitamin C Daily n=24 participants at risk Ferrous sulfate 300mg tablet and vitamin C 500mg tablet taken by mouth every day for 12 weeks Ferrous Sulfate 300Mg Tablet: oral dose of Ferrous Sulfate (300 mg) every day versus every other day along with vitamin C Vitamin C 500Mg tablet: Vitamin C 500 Mg tablet every day versus every other day along with ferrous sulfate	Total/All Participants n=51 participants at risk Overall proportion of patients with adverse effects.
Gastrointestinal disorders Constipation	22.2% 6/27 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	25.0% 6/24 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	23.5% 12/51 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.
Gastrointestinal disorders Nausea	25.9% 7/27 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	16.7% 4/24 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	21.6% 11/51 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.
Nervous system disorders Headache	25.9% 7/27 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	16.7% 4/24 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	21.6% 11/51 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.
Respiratory, thoracic and mediastinal disorders Breathlessness	25.9% 7/27 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	16.7% 4/24 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	21.6% 11/51 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.
Gastrointestinal disorders Heartburn	29.6% 8/27 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	8.3% 2/24 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	19.6% 10/51 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.
Gastrointestinal disorders Abdominal pain	18.5% 5/27 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	8.3% 2/24 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	13.7% 7/51 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.
Gastrointestinal disorders Diarrhea	18.5% 5/27 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	8.3% 2/24 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	13.7% 7/51 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.
Gastrointestinal disorders Vomiting	11.1% 3/27 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	4.2% 1/24 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.	7.8% 4/51 • Adverse event data was collected at weeks 4, 8, and 12. Adverse events were documented at each follow-up according to the Common Terminology Criteria for Adverse Events (Version 5.0). A modified adverse effects of oral iron questionnaire was used.

Additional Information

Dr. Yulia Lin

Sunnybrook Health Sciences Centre

Phone: 4164804042

Email: yulia.lin@sunnybrook.ca

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place