摘要:

AbstractThe relative roles of non‐heme and heme iron in preventing iron deficiency are reviewed. While it has been difficult to demonstrate, in different population groups, any correlation between the intake of non‐heme iron and iron deficiency, such correlations have been found between the intake of meat and iron deficiency. Alternative interpretations of the these findings are discussed.The absorption of non‐heme iron under experimental and physiological conditions is reviewed. Under experimental conditions, and in acute iron deficiency absorption is invariably very good, but under long‐term conditions of prophylaxis absorption is reduced and side effects lead to non‐compliance of patients. This suggests studies of heme iron for prophylactic purposes.Repeated studies between 1945 and 1978 have failed to prove the efficacy of iron fortification, and some suggest that even tablets may not be efficient in the prevention of iron deficiency. Concern about possible negative effects of prophylaxis with non‐heme iron has increased lately, particularly when iron tablets mask the anemia of gastrointestinal cancer. Heme iron has only a small advantage in these respects, namely that doses and the maximal absorption are lower.In different studied meals, the heme iron absorption is usually higher than the non‐heme iron absorption, probably because the absorption of non‐heme iron is inhibited by several constituents of the meal.The prevalence of iron deficiency is reviewed. It is suggested that directed prophylaxis with heme iron in tablet form, which can be directed towards at‐risk groups and away from groups in the gastrointestinal cancer age, tablets which can be taken with meals and without side effects should be studied as an alternative to generalized i

ISSN:0001-6101    

DOI:10.1111/j.0954-6820.1979.tb01110.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractA simplified dose response study showed no significant reduction of absorption when the dose was increased from 0.9 to 4.2 mg hemoglobin iron, where absorption was about 20 per cent, but a significant reduction to 11 per cent when dose was increased from 4.2 to 19 mg hemoglobin iron. Nor was any significant absorption inhibition found when 3.5 mg hemoglobin iron were given together with an oatmeal porridge test meal. In contrast, this meal reduced non‐heme, ferrous iron absorption from 16.7 to 5.5 per cent.When given on a fasting stomach, no significant difference was found between absorption of hemoglobin and non‐heme iron at 3.5 mg dose levels. Numerically, hemoglobin iron was slightly superior.Meat products, expected to facilitate absorption of non‐heme iron were also studied, either given alone or together with a test meal. Mean absorptions of 3.5‐10 mg hemoglobin iron in different meals varied between 14.7 and 18.9 per cent, as compared to mean absorptions of non‐heme iron between 5.5 and 7.9 per cent.In contrast, hemoglobin iron absorption was reduced to only 0.8 to 7.6 per cent when baked products, such as bread or liver‐paté were studied. Even so, however, mean hemoglobin iron absorptions were 2 to 3 times higher than those of non‐heme iron.The cause of the absorption inhibition in bread was studied. No correlation could be found to the content of bran. No significant inhibition was found when unbaked, sour leaven dough was eaten. However, when hemoglobin was heated to baking temperature for baking times, absorption was reduced as in bread. Hemoglobin breakdown during prolonged heating is thus suggested.No significant difference was found between hemoglobin capsules and hemoglobin tablets.The present results suggest that hemoglobin fortification can contribute substantial amounts of absorbed iron. A single meal containing about 5 mg hemoglobin iron seems to provide about 0.8 mg of absorbed iron. This alone corresponds to the total iron requirements of a woman with a loss of 30 ml blood pe

ISSN:0001-6101    

DOI:10.1111/j.0954-6820.1979.tb01111.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThere are 4 reasons to examine heme iron absorption.1Vegetabllic diets and iron deficiency anemia in developing countries2difficulties to refill iron stores in women in industrialized countries3non‐use of cattle hemoglobin for human nutrition, and4differences in absorption between heme and non‐heme iron. Twenty‐eight different preparations and combinations of59Fe‐heme were fed to 84 volunteers with latent iron deficiency.Four methods to prepare heme were tested. UV‐spectrophotometry, used to examine the degree of heme polymerization showed unprecise spectra for heme prepared with acetic acid acetone, which suggests polymerization. About 40 mg histidine/mg heme sharpened spectra, probably since dihistidine‐heme monomers were formed.Calculations described earlier indicate that the net absorption increase when the diet is supplemented with 20 mg ferrous iron daily, and when the iron is given with meals, is only 0.8 mg/day. In contrast, it has been calculated that if 20 mg hemoglobin iron are given it is 2.2 mg/day. If 20 mg heme iron in ordinary or enteric‐coated capsules was given alone or together with buffering substances, absorption was unsatisfactory (about 0.15 mg iron).It was also unsatisfactory (about 0.4 mg) from solutions containing glycine or histidine. However, satisfactory absorptions (about 2 mg) were obtained from a buffered, pH 8 water solution of hemin containing nicotinic acid, and of an oil solution of hemin‐

ISSN:0001-6101    

DOI:10.1111/j.0954-6820.1979.tb01112.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractIf hemoglobin or globin are to be used for food fortification, it becomes necessary to ascertain that the nutritional value of fooods so fortified does not become unsatisfactory. The chemical score of isolated globin is as low as between 3 and 7, with isoleucin as the limiting amino‐acid, and consequently the biological value (25.5) and net protein utilization (25.9) are also low. However, the true digestibility is high (101 per cent).During the industrial processing, hemoglobin may be frozen, bleached, or separated into heme and globin. Bleaching may reduce the digestibility, and separation may cause the loss of some isoleucin, but these effects seem minor.If cereals are fortified with about 1.5 per cent by weight of hemoglobin (supplying about 15 per cent of the nitrogen) the biological value of the cereals is improved by about 20 per cent. When meat products fortified with 1‐10 per cent by weight of hemoglobin (supplying about 4‐23 per cent of the proteins) were included in meals, the meals had chemical scores over 90, which is well accep

ISSN:0001-6101    

DOI:10.1111/j.0954-6820.1979.tb01113.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

ISSN:0001-6101    

DOI:10.1111/j.0954-6820.1979.tb01114.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY