Short-term ferrous sulfate supplementation in female blood donors

BACKGROUND: Iron deficiency is a public problem in women, which contributes to the high percentage of deferred blood donations in this group. This study evaluated the effect of iron supplementation in improving iron stores to promote safe blood donation in women. STUDY DESIGN AND METHODS: A total of 412 female blood donors were randomly recruited for the study. The volunteers were scheduled for an initial visit and three subsequent visits at 4-month intervals for possible repeat donation. Each volunteer was given 21 tablets of 150 mg of ferrous sulfate or placebo to be taken three times daily for 1 week after each blood donation. Their hemoglobin (Hb) concentration, hematocrit (Hct), serum ferritin, total iron-binding capacity (TIBC), and percent saturation of the TIBC were tested throughout the course of the study. RESULTS: The group taking ferrous sulfate showed no significant difference between the mean initial and final result for any of the values other than Hb values, whereas there was a significant decline in mean Hb, Hct, serum iron, serum ferritin, and percent saturation in the group taking placebo. Hb concentrations declined significantly in both groups; however, it was more severe in the placebo group when compared to the ferrous sulfate group. The relative risk of iron deficiency in placebo group was 3.6 (95% confidence interval = 1.73-7.74). CONCLUSION: The results indicate that supplementation therapy can be considered as one of the strategies to promote safe blood donation in women. A quantity of 150 mg of elemental iron per day as ferrous sulfate, however, is not the correct dose for Iranian female donors.     

Iron stores in remunerated blood donors as evaluated by plasma ferritin levels

This study was undertaken to investigate body iron stores in so-called remunerated blood donors as well as to evaluate the sensitivity of hemoglobin determination in detecting iron deficiency in two populations of blood donors. The authors studied 522 male donors who were divided into three groups: Group I, first-time volunteer donors with hemoglobin levels greater than or equal to 13 g per dl; Group II, remunerated donors with hemoglobin levels greater than or equal to 13 g per dl; and Group III, remunerated donors rejected because their hemoglobin levels were less than 13 g per dl. Iron stores were evaluated with an enzyme-linked immunosorbent assay for plasma ferritin. In Group I, 4.5 percent were iron-deficient with a mean ferritin value of 55.3 ng per ml; in Group II, 59.7 percent were iron deficient with a mean ferritin level of 17.4 ng per ml, and in Group III, 82.5 percent were iron-deficient and the mean ferritin level was 8.4 ng per ml. The last values represent the highest percentage of iron deficiency and the lowest mean ferritin value thus far reported. In Group I, hemoglobin determination had a sensitivity of 95 percent in detecting iron deficiency, but in Group II had only 40 percent sensitivity. These results indicate that a more accurate and reliable test, such as a plasma or serum ferritin determination, may be necessary to detect iron deficiency in blood donors when they donate more than five times per year, particularly those who are remunerated.     

The value of routine ferritin measurement in blood donors

BACKGROUND: Iron store deficiency is a common side effect of whole blood donation. Early recognition and reversal of excessive iron loss may avoid symptomatic iron store depletion in blood donors and reduce volunteer loss due to iron deficiency (ID) anemia. STUDY DESIGN AND METHODS: Between 1996 and 2009, a total of 160,612 visits with the intention to donate blood by 23,557 healthy volunteers were recorded at our center. As of 2004, routine serum ferritin testing and additional counseling of donors at risk for donation‐induced anemia were implemented. We analyzed the impact of this measure on the hemoglobin (Hb) levels and anemia occurrence in our donor population and in particular in women of childbearing age. Donation rejections due to low Hb counts, the intervals to next donation, and return rates thereafter were also assessed. RESULTS: The introduction of routine serum ferritin analysis resulted in an increase of mean Hb levels in blood donors particularly in women of childbearing age. The incidence of predonation anemia and donation ineligibility due to a low Hb concentration decreased significantly. The return intervals of donors rejected on account of low Hb levels were shortened; however, the return rates thereafter were also curtailed. CONCLUSIONS: Systematic serum ferritin measurements allowed an optimized management of ID in our donors and efficacious prevention of ID anemia.     

Iron supplementation for menstruating female blood donors

Depletion of body iron stores is a major factor limiting regular blood donations by menstruating females. To determine if regular iron supplementation would solve this problem, we conducted a double-blind study in which menstruating female donors were randomly placed into one of three groups: one taking 39 mg elemental iron, a second taking 39 mg of iron plus 75 mg vitamin C, and a third taking 100 mg vitamin C daily. The women were requested to donate every 8 weeks for at least 1 year. Blood samples were taken on each donation for measurements of hemoglobin, total iron binding capacity (TIBC), and ferritin. In the two groups taking iron supplements hemoglobin and ferritin increased from baseline values and the TIBC decreased. The vitamin C control group showed decreases from baseline for hemoglobin and ferritin and increases in TIBC. Differences between groups taking iron supplements and the group not taking supplements were highly significant. Drop-out from the study was due to various causes; however, iron intolerance was uncommon. Minimal daily iron supplementation was beneficial in maintaining body iron stores and hemoglobin levels in menstruating females on a schedule of blood donation as often as every 8 weeks.     

Evaluation of iron status in women identified by copper sulfate screening as ineligible to donate blood

Assessment of venous hemoglobin (Hb), serum ferritin, and zinc protoporphyrin (ZPP) levels was carried out in women identified by CuSO4 screening as ineligible to donate blood. The correlation of log ferritin with ZPP was relatively poor (r = -0.580) but significant (p greater than 0.01). However, a ZPP level of 2.0 micrograms per g Hb or greater (upper limit of normal for first-time female donors) showed a predictive value of 0.85 for a ferritin level of 12 ng per ml or less in these donors. The correlation of hemoglobin concentration with ZPP level was significant (r = -0.667; p less than 0.001) in blood donors with ferritin levels at or below 12 ng per ml. ZPP level appears to be increased in iron-depleted (hypoferritinemic) blood donor in whom animals had developed or was developing (Hb less than 12.5 g/dl). Although direct measurements of venous hemoglobin and ferritin levels most accurately evaluate such blood donors, these tests are time-consuming and expensive and are currently not adaptable to bloodmobile operations. Copper sulfate screening has proved feasible in the bloodmobile setting, and the measurement of ZPP level has been used for mobile screening for lead poisoning. ZPP may be an inexpensive and useful screening test to determine a subset of donors who should receive supplemental iron or reduce their frequency of blood donation.     

Screening with zinc protoporphyrin for iron deficiency in non-anemic female blood donors

Iron-depleted donors are at increased risk of developing anemia; if these donors could be identified by a screening test, iron supplementation or decreased donation frequency could be considered. Tests to determine serum ferritin, blood hemoglobin, and erythrocyte (Erc)-zinc protoporphyrin concentrations were examined in 679 consecutive female blood donors to identify donors with non-anemic iron deficiency. The test to determine serum ferritin is expensive and slow, whereas the two latter tests are rapid and less costly and could therefore be used for screening. Women in the fertile age groups had the lowest average serum ferritin values. In all, 93 women (13.7%) had depleted iron stores, as indicated by serum ferritin concentrations less than 14 micrograms/L. In these women, a much better correlation was found between Erc-zinc protoporphyrin and serum ferritin (rs = -0.49, P less than 0.001) than between blood hemoglobin and serum ferritin (rs = 0.31, P less than 0.01). These findings suggest that measurement of Erc-zinc protoporphyrin is superior to that of blood hemoglobin in identifying donors with non-anemic iron deficiency.     

Daily doses of 20 mg of elemental iron compensate for iron loss in regular blood donors: a randomized, double-blind, placebo-controlled study

BACKGROUND: A considerable number of regular blood donors develops an iron deficiency, and the exact amount of iron required to compensate for the iron loss from whole-blood donation in males and females is still unknown. STUDY DESIGN AND METHODS: A total of 526 regular blood donors (289 male and 237 female) were randomly assigned to treatment with either 40 mg, 20 mg, or 0 mg per day of elemental iron as ferrous gluconate for a period of 6 months, during which one unit of whole blood was collected on four occasions (males) or three occasions (females). Hemoglobin level, serum ferritin, and soluble transferrin receptor levels were measured before each donation. RESULTS: Daily doses of either 40 mg or 20 mg of elemental iron adequately compensated for iron loss in males, who gave blood at 2-month intervals, but did not result in a positive iron balance or an increase in storage iron as reflected by the logarithm of the ratio of transferrin receptor to ferritin concentration. In females, who donated at 3-month intervals, the same daily doses not only restored the iron balance but also led to an increase in storage iron. The number of gastrointestinal side effects due to iron supplementation (12%) was only slightly higher in both iron groups than in the placebo group. CONCLUSION: The results of this study indicate that 20 mg of elemental iron per day can adequately compensate for iron loss in males and females who donate whole blood up to four (females) or six times per year (males).     

Volunteer blood donors who fail the copper sulfate screening test

Volunteers attending blood donor sessions who fail the copper sulfate screening test merit an explanation of why they are considered ineligible to donate. During a 30-month period, 0.24 percent of men and 2.8 percent of women attending blood donor sessions in the northern region of England failed this test. Their hematologic status was determined by performing complete blood counts on a venous blood specimen and measuring ferritin as an indication of iron stores in a representative sample of approximately 10 percent. Normal blood counts were found in some donors, while others had severe degrees of anemia, and such discrepancies could be clarified only by hemoglobin determinations. Iron deficiency was very common in deferred donors, including 36 of the 88 with normal blood counts in whom ferritin assays were performed. Microcytic blood cells, a hallmark of iron deficiency, were found to be a relatively insensitive measure of low iron stores, except at low levels of hemoglobin. By a check of a venous sample, the hematologic status of most volunteers failing the copper sulfate screening test can be ascertained, and appropriate review, investigation, and treatment can be undertaken.     

The impact of intensive serial plasmapheresis and iron supplementation on iron metabolism and Hb concentration in menstruating women: a prospective randomized placebo-controlled double-blind study

BACKGROUND: Iron (Fe) depletion is common among regular whole-blood donors, but can be prevented through regular oral Fe supplementation. Little is known, however, about the Fe metabolism of donors undergoing intensive plasmapheresis. These donors lose considerable amounts of blood drawn for laboratory analyses and remaining in the disposable plastic sets. STUDY DESIGN AND METHODS: Menstruating women were enrolled in a prospective placebo- controlled double-blind study. One hundred women were randomly allocated to receive either 100 mg of elemental Fe per day or placebo over 24 weeks and asked to donate plasma at 1-week intervals. Hb was determined before each plasmapheresis. Ferritin, transferrin, and Fe concentration and reticulocyte count were measured every 4 weeks. RESULTS: Thirty donors in the placebo group and 29 receiving Fe completed the study. The total mean blood loss was 526 mL in the placebo group and 546 mL in the Fe arm (p=0.271). The number of donations with Hb values lower than 12.5 g per dL requiring prolongation of the time interval until the next plasmapheresis was significantly greater in the placebo arm. In the placebo group (n=30), ferritin levels began to decline significantly 4 weeks after entry. When the study was completed, Hb concentration and reticulocyte count also were found to be significantly lower in the placebo group than in the Fe study arm (p=0.028 and p=0.036, respectively). Hb, ferritin, and transferrin levels and reticulocyte counts did not change significantly in the Fe group during the observation period. CONCLUSION: Menstruating women undergoing regular plasmapheresis at short intervals are prone to develop Fe depletion. This can be prevented by regular Fe intake. Laboratory analyses in product plasma instead of serum gained from whole-blood samples could be an alternative to reduce blood loss.     

Evaluation of iron status of Finnish blood donors using serum transferrin receptor

The maximum allowable frequency of blood donations has been set so that donations should not cause anaemia or depletion of iron stores. However, it has not been determined precisely how often blood donations result in depletion of iron stores. In the present study we have evaluated iron status in blood donors using serum ferritin and transferrin receptor (TfR) concentrations. The elevation of serum TfR has been reported to be the most sensitive indicator of depletion of iron stores. On the basis of ferritin values, in men who donate frequently the amount of body iron is reduced to a level very close to that found in women donating blood for the first time. When an elevation of serum TfR above 4.0 mg L-1 was used as a stringent definition of complete iron depletion, it was estimated that 17% of frequently donating women had completely lost their iron stores, while the corresponding value for men was 8%. The fact that a considerable proportion of the female blood frequent donors have completely depleted their iron stores raises the question whether the iron status of female frequent blood donors should be routinely monitored using serum transferrin receptor measurements.     

Iron Balance in Regular Blood Donors

SUMMARY: BACKGROUND: Numerous reports have shown that iron stores decrease in blood donors after donation. As we need healthy donors, it is essential to test hemoglobin and ferritin levels for preventing reduced of iron stores in donors. METHODS: This study was conducted on 235 healthy men. The donors were divided into three groups: group I) control group with no donation; group II) case group 1 with two donations within 1 year; group III) case group 2 with three donations within 1 year. RESULTS: The mean level of hemoglobin was 15.9 and 14.7 g/dl in the control group and in the case group, respectively (p < 0.0000). The mean level of serum ferritin in group I, II and III, was 108, 56 and 26 μg/l, respectively (p < 0.0000). When studying various stages of iron deficiency in donors, it could be shown that 58% of group III donors but only 1% of control group donors had a negative iron balance. Moreover, iron deficiency anemia was observed in 20% of group III donors. CONCLUSION: Just measuring the hemoglobin level is not sufficient for selecting donors. In addition, testing of the ferritin level and iron supplementation are recommended in regular donors with more than one donation per year.     

Iron replacement therapy in the routine management of blood donors

BACKGROUND: Iron depletion or deficiency in blood donors frequently results in deferrals for low hemoglobin (Hb), yet blood centers remain reluctant to dispense iron replacement therapy to donors. STUDY DESIGN AND METHODS: During a 39‐month period, 1236 blood donors deferred for a Hb level of less than 12.5 g/dL and 400 nondeferred control donors underwent health history screening and laboratory testing (complete blood counts, iron studies). Iron depletion and deficiency were defined as a ferritin level of 9 to 19 and less than 9 µg/L in females and 18 to 29 and less than 18 µg/L in males. Deferred donors and iron‐deficient control donors were given a 60‐pack of 325‐mg ferrous sulfate tablets and instructed to take one tablet daily. Another 60‐pack was dispensed at all subsequent visits. RESULTS: In the low‐Hb group, 30 and 23% of females and 8 and 53% of males had iron depletion or deficiency, respectively, compared with 29 and 10% of females and 18 and 21% of males in the control group. Iron‐depleted or ‐deficient donors taking iron showed normalization of iron‐related laboratory parameters, even as they continued to donate. Compliance with oral iron was 68%. Adverse gastrointestinal effects occurred in 21% of donors. The study identified 13 donors with serious medical conditions, including eight with gastrointestinal bleeding. No donors had malignancies or hemochromatosis. CONCLUSION: Iron depletion or deficiency was found in 53% of female and 61% of male low‐Hb donors and in 39% of female and male control donors. Routine administration of iron replacement therapy is safe and effective and prevents the development of iron depletion and deficiency in blood donors.     

The effect of oral iron supplementation on erythropoiesis in autologous blood donors

The effect of oral iron supplementation on erythropoiesis was studied prospectively in 34 autologous blood donors. The subjects, all of whom were to undergo total hip surgery, had normal iron status at the start of the study. During the preoperative period, in which 4 units of blood were collected, 17 patients received oral iron supplementation with 287 mg of ferrous sulfate (105 mg of elemental iron/day), while 17 patients did not use any iron supplementation. Oral iron supplementation during the 4-week preoperative period lessened the decrease in ferritin levels after two phlebotomies. Neither the decrease in hemoglobin nor the increase in erythropoietin levels was influenced by iron supplementation. In both iron-supplemented and control patients, serum erythropoietin levels returned to initial values within a few days after surgery. In autologous blood donors with a normal iron status, the use of supplemental iron does not affect erythropoiesis and is insufficient to maintain iron stores.     

Iron stores in male blood donors evaluated by serum ferritin

Iron stores were evaluated by serum ferritin measurements in 1348 male blood donors. Blood donation was associated with a decrease in serum ferritin concentrations. First-time donors (n = 21) had a geometric mean serum ferritin concentration of 52 micrograms per l, and multiple-time donors (n = 1327) of 36 micrograms per l (p less than 0.01). In the donating population, 6.0 percent had serum ferritin values less than 15 micrograms per l (i.e., depleted iron stores), 33.9 percent had values from 15 to 30 micrograms per l (i.e., reduced iron stores), 52.5 percent had values from 31 to 90 micrograms per l, and 7.6 percent had values greater than 90 micrograms per l (i.e., normal iron stores). The frequency of donations per year was more predictive of decreased iron stores than the number of lifetime donations. Serum ferritin showed a moderate fall up to the fourth donation (p less than 0.001); thereafter serum ferritin levels showed only minor insignificant changes. An increase in donation frequency was accompanied by a significant decrease in serum ferritin; values less than 15 micrograms per l were found in 1.3 percent of donors bled two times per year, in 6.0 percent bled three times per year, and in 7.9 percent bled four times per year. Regular monitoring of iron stores by serum ferritin in blood donors seems justified in order to identify those with depleted iron stores who will benefit from iron supplementation.     

Iron supplementation and 2-unit red blood cell apheresis: a randomized, double-blind, placebo-controlled study

BACKGROUND: The benefits of 2-unit red blood cell (RBC) apheresis are evident, but iron depletion may be a limiting factor in using this technology. Regular iron supplementation may allow a better utilization of this technique. STUDY DESIGN AND METHODS: In this study, 260 regular blood donors donated 2-unit RBCs on each of a total of seven visits at intervals of 8 to 10 weeks. The volunteers were randomly assigned to receive 100 mg of iron(II) or placebo daily. Group A received iron capsules after the first three donations, and Group B after the second three donations, respectively. Hemoglobin, serum ferritin, and serum iron were measured before each donation. RESULTS: Mean serum ferritin concentration decreased after each donation in the placebo phase of both treatment groups, but it remained largely constant during the iron phase in Group A, and even increased during the iron phase in Group B. CONCLUSION: Regular iron supplementation prevents iron depletion in the majority of donors after 2-unit RBC apheresis within an 8- to 10-week period.     

Iron deficiency in blood donors: the REDS-II Donor Iron Status Evaluation (RISE) study

BACKGROUND: Blood donors are at risk of iron deficiency. We evaluated the effects of blood donation intensity on iron and hemoglobin (Hb) in a prospective study. STUDY DESIGN AND METHODS: Four cohorts of frequent and first‐time or reactivated (FT/RA) blood donors (no donation in 2 years), female and male, totaling 2425, were characterized and followed as they donated blood frequently. At enrollment and the final visit, ferritin, soluble transferrin receptor (sTfR), and Hb were determined. Models to predict iron deficiency and Hb deferral were developed. Iron depletion was defined at two levels: iron deficiency erythropoiesis (IDE) [log(sTfR/ferritin) ≥ 2.07] and absent iron stores (AIS; ferritin < 12 ng/mL). RESULTS: Among returning female FT and RA donors, 20 and 51% had AIS and IDE at their final visit, respectively; corresponding proportions for males were 8 and 20%. Among female frequent donors who returned, 27 and 62% had AIS and IDE, respectively, while corresponding proportions for males were 18 and 47%. Predictors of IDE and/or AIS included a higher frequency of blood donation in the past 2 years, a shorter interdonation interval, and being female and young; conversely, taking iron supplements reduced the risk of iron depletion. Predictors of Hb deferral included female sex, black race, and a shorter interdonation interval. CONCLUSIONS: There is a high prevalence of iron depletion in frequent blood donors. Increasing the interdonation interval would reduce the prevalence of iron depletion and Hb deferral. Alternatively, replacement with iron supplements may allow frequent donation without the adverse outcome of iron depletion.     

Characteristics of a donor population in western Venezuela

To determine the characteristics of blood donors in western Venezuela, we collected data from 1983 to 1985 on 31,320 volunteer donors at the Blood Bank of the State of Zulia in Maracaibo. Fifty-nine percent of the donors were blood group O, 30 percent were group A, 9 percent were group B, and 2 percent were group AB. Most of the donors (93%) were Rh positive. One percent of donors had positive reactions to hepatitis B surface antigen, 3.15 percent for syphilis, 1.43 percent for antibodies to Trypanosoma cruzi, and 0.32 percent to human immunodeficiency virus antibodies. About one-half of the donors were between 18 and 30 years old, and only 10 percent were women. To determine if iron deficiency anemia was a cause for the small size of the female donor pool, we measured serum ferritin in 50 first-time female donors. Ten of these (20%) had serum ferritin values below normal, and the distribution of serum ferritin levels of all 50 was very similar to that reported for frequent donors in Europe and the United States, with a clustering of ferritin values between 10 and 70 ng per ml. The data indicate that blood donors in western Venezuela are markedly different from those in the United States and that iron supplementation may be indicated for female Venezuelan donors.     

Switching iron‐deficient whole blood donors to plateletpheresis

BACKGROUND: Iron deficiency is a frequent side effect of whole blood (WB) donation. In contrast, less red blood cell loss and therefore less iron loss results from plateletpheresis. STUDY DESIGN AND METHODS: WB donors presenting a decrease in either hemoglobin (Hb) or ferritin levels were offered to switch to plateletpheresis with or without iron supplementation. We analyzed the effect of this intervention on deferral rates for an insufficient Hb level in 168 donors. Further, we assessed how this intervention affected Hb and ferritin levels, anemia occurrence, and platelet (PLT) concentrate yields in the donors who presented at least four successive times for thrombapheresis. RESULTS: Switching WB donors to repetitive plateletpheresis procedures resulted in an increase of median Hb (+12 g/L, p < 0.001) and ferritin (+15.5 ng/mL, p = 0.002) values. Anemia and deferral rates were reduced by 23% (p = 0.004) and 13% (p < 0.001). Between high‐ and low‐frequency apheresis donors, no significant differences in Hb and ferritin levels were found. Similarly, discrepancies in Hb and ferritin values between donors that adopted iron supplementation and those who did not were insignificant. The median PLT concentrate yield was 5.43 × 10¹¹ PLTs. CONCLUSION: Switching iron‐deficient WB donors to plateletpheresis was an effective intervention that permitted us to correct low Hb and ferritin levels while retaining donors in our pool.     

Decreased levels of ferritin,mild thrombocytosis,and increased erythropoietin are sequential events among frequent plateletpheresis donors: Implication for a ferritin screen

BackgroundIt is generally recognized that repeat apheresis increases the risk for iron deficiency, thus may impact on the blood homeostasis. With regard to donor vigilance, we clarified the mid- to long-term effects of plateletapheresis by comparing the most frequent donors with the first-time ones in hematological and biochemical tests.MethodsLevels of erythropoietin (EPO), hemoglobin (Hb) and ferritin were analyzed in double-unit (500 mL whole blood or 6 × 10¹¹ apheresis platelets) donations in three male cohorts, with identifiers of first-time whole-blood donors (n = 30), first-time platelet donors transited from maximal whole blood to apheresis (n = 30) and frequent donors subjected to extreme plateletpheresis (n = 90), respectively. According to the number of donations, the last earnest cohort, who donate almost 24 times a year, was further subdivided into three groups– casual (76–120 life-time donations in 5 years), mediocre (121–168 within 7 years) and enthusiastic (≥169 within 7 years and a month).ResultsRegardless of the donation experience in whole blood or plateletpheresis, iron deficiency (serum ferritin concentrations <15 μg/L) was identified in all earnest cohorts. The ferritin means were significantly lower in plateletpheresis groups, with the lowest values in the enthusiastic group. EPO levels showed a significant inverse correlation with ferritin (p = 0.015, r = –0.224). Long-term earnest donors had the lowest iron stores accompanied by a later thrombocytosis and a final increase in EPO was revealed.ConclusionRegular ferritin screens are crucial to ensure a high level of donor health protection.     

Carbonyl iron for short-term supplementation in female blood donors

A randomized, double-blind trial of iron replacement after repeated blood donation was conducted in 75 menstruating women; 51 completed the study. Volunteers were assigned randomly to one of three treatment groups: 1) carbonyl iron (nontoxic elemental iron powder), 600 mg; 2) ferrous sulfate, 300 mg (60 mg Fe++); or 3) placebo, each given three times daily for 1 week immediately after blood donation. Blood samples obtained initially and 56 days later were tested for hemoglobin, mean corpuscular volume (MCV), free erythrocyte protoporphyrin, serum ferritin, serum iron, total iron binding capacity (TIBC), and percent saturation of TIBC. The prevalence of gastrointestinal side effects was similar in both groups taking iron. At the end of the study there was no laboratory evidence of change in iron status in women who received carbonyl iron (n = 15). In those treated with ferrous sulfate (n = 17) the mean TIBC increased (p less than 0.001), and in the placebo group (n = 19) there were decreases in mean MCV (p less than 0.01), serum ferritin (p less than 0.001), and percent saturation (p = 0.027) with an increase in mean TIBC (p = 0.004). Carbonyl iron seems to be effective for short-term iron replacement in repeat blood donors and may have the advantage of decreased or absent risk of poisoning if accidentally ingested by children.