Vitamin C and anaemia--news from Sweden.
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Anemia, Hypochromic↗
Biomedical subjects
L Hallberg
Publications and source records attributed to L Hallberg.
Iron absorption in relation to iron status. Model proposed to express results to food iron absorption measurements.
The absorption from a 3 mg dose of ferrous iron was measured in 250 male subjects. The absorption was related to the log concentration of serum ferritin in 186 subjects of whom 99 were regular blood donors (r = -0.76), and to bone marrow haemosiderin grading in 52 subjects with varying iron status. The purpose was to try and establish a percentage absorption from such a dose that is representative of subjects who are borderline iron deficient. This information is necessary for food iron absorption studies in order (1) to calculate the absorption of iron from the diet at a given iron status and (2) compare the absorption of iron from different meals studied in different groups of subjects by different investigators. The results suggest that an absorption of about 40% of a 3 mg reference dose of ferrous iron is given in a fasting state, roughly corresponds to the absorption in borderline-iron-deficient subjects. The results indicate that this 40% absorption value corresponds to a serum ferritin level of 30 microgram/l and that food iron absorption in a group of subjects should be expressed preferably as the absorption corresponding to a reference-dose absorption of 40%, or possibly a serum ferritin level of 30 microgram/l.
Absorption↗
Bioavailability of iron from different meals.
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Absorption↗
[Heme iron--an irrational and expensive preventive and therapeutic form].
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Costs and Cost Analysis↗
The measurement of food iron absorption in man. A methodological study on the measurement of dietary non-haem-Fe absorption when the subjects have a free choice of food items.
1. The present study was considered as a first step to develop a method to measure food iron absorption from realistic common meals prepared and consumed by the subjects themselves in their own homes. The absorption of Fe from the meals was measured by means of the extrinsic-tag method modified to allow for a free choice of food items. 2. The mean Fe intake was 2.79 mg and the mean Fe absorption approximately 0.30 mg. The Fe status of the subjects corresponded to 31.5% absorption from a reference dose solution containing 3 mg elemental Fe as ferrous ascorbate. The variation in food Fe absorption obtained in this field study was found to be of the same magnitude as that obtained in studies performed under more controlled conditions as in the laboratory. 3. The conclusion was drawn that the proposed method could be used in realistic field studies aimed at, for example, explaining or preventing a high prevalence of deficiency. A suffciently long run-in period and a careful instruction of the subjects was considered essential for the design of future field studies.
Adult↗
Absorption of iron from breakfast meals.
The absorption of nonheme iron from nine common Western type breakfasts was studied in 129 subjects using extrinsic labeling with radioiron. In one group the iron absorption from a continental type of breakfast served with coffee was standardized against the absorption from a reference dose of derrous ascorbate (3 mg Fe). In all subsequent experiments the absorption from this breakfast was compared with one of the other breakfast meals served on alternate days and each labeled with a different radioiron isotope. The bioavailability of iron in the different breakfast meals varied markedly. There was almost a 6-fold idfference in absorption (0.07 to 0.40 mg) despite of the fact that the iron content only varied from 2.8 to 4.2 mg. The most marked effect was seen with tea which reduced the absorption to less than half and with orange juice which increased the absorption two and a half times. The present findings must be considered when giving dietary advice to groups of subjects who are known to have a critical iron balance. The present results also imply that an evaluation of the iron nutrition in a population cannot only be based on the daily dietary intake of iron but must also include the bioavailability of iron in frequently consumed meals.
Adolescent↗
Haemoglobin concentration and peripheral blood cell counts in women. The population study of women in Göteborg 1968-1969.
Hb concentration, PCV, erythrocyte and leucocyte counts in the peripheral blood, MCV, MCH and MCHC in a population sample of 1462 women in ages between 38 and 60 years are presented. In addition, a description is given of thrombocyte counts in 38-year-old women. Significant differences with age were found for Hb concentration and PCV and for leucocyte counts. High correlations were found between Hb and PCV in the various age groups studied, while lower correlations were found between erythrocyte counts on one hand and Hb or PCV on the other. There was an overrepresentation of smokers among women with high Hb values and among those with high leucocyte counts. The higher leucocyte counts in the youngest age groups could be explained by the larger number of smokers in these ages. Thrombocyte counts were lower in smoking than in non-smoking women.
Adult↗
Characteristics of anaemic women. The population study of women in Göteborg 1968-1969.
Anaemic women (Hg concentration less than 120 g/l) who participated in a population study of women in Göteborg, Sweden were compared to the women in the population sample as a whole. Due to the way of sampling and a high participation rate the sample was representative of women in Göteborg in the ages studied (age strata between 38 and 60). In the same way the anaemic women were representative of anaemic women in the same general population. Iron deficiency was found to be the main reason for the anaemia in the ages of 38-50 years. Except for big menstrual blood losses in anaemic women no reason for iron deficiency could be found. History of infectious diseases was about as common in anaemic women as in women in the total population sample. Sleeping habits, time off work and physical activity at work and during leisure time were similar in anaemic women and in women in the general population. The proportion of women who reported subjective feeling of tiredness was also similar.
Adult↗
Serum iron and transferrin saturation in women with special reference to women with low transferrin saturation. The population study of women in Göteborg 1968-1969.
Serum iron and total iron binding capacity (TIBC) were determined in a population sample of 1462 women in age strata between 38 and 60. Serum iron and TIBC values were similar in the various ages studied but with a slight trend towards higher serum iron and lower TIBC values in the upper ages. Transferrin saturation was used to divide the material arbitarily into women with and without iron deficiency. The dividing point chosen was 16%. The women thus defined as iron deficient had lower mean haemoglobin values than women in the total population sample and were more often anaemic. They had also lower MCV, MCH and MCHC indices than women in the total population sample. Of these indices, MCH seemed to discriminate the state of iron deficiency better than MCV and MCHC. Except for an increased mean menstrual blood loss no obvious cause of iron deficiency could be found in these women with low transferrin saturation.
Adult↗
Effect of animal proteins on the absorption of food iron in man.
The way in which meat and fish act to promote the absorption of nonheme iron in food is not known. The present paper is a report of the results of a series of studies aimed at obtaining some insight into the mechanism of action of meat and other animal proteins on the absorption of food iron. Beef, fish, chicken and calf thymus all increased the iron absorption to about the same extent. Neither egg albumin, cysteine or a water extract of beef did, however, affect the absorption of food iron. Beef increased the absorption of a solution of inorganic iron given without food only when the iron salt was trivalent or when sodium phytate was added to the solution. It was concluded that meat acts by counteracting luminal factors that inhibit iron absorption. The most probable mechanism for this action is formation of a luminal carrier which transports the iron to the mucosal cell membrane.
Achlorhydria↗
The effect of parietal cell vagotomy and selective vagotomy with pyloroplasty on iron absorption. A prospective randomized study.
Iron absorption from a composite meal was studied in 37 male patients before and 1 year after parietal cell vagotomy (PCV) and selective vagotomy with pyloroplasty (SV + P) in a prospective randomized series. The ability to absorb dietary non-haem iron was studied by relating in each subjects the food iron absorption to the absorption from a small dose of ferrous iron, which has been shown to be unaffected by gastric surgery. After both PCV and SV + P there was a malabsorption of food iron which was statistically significant in patients with increased iron requirements caused by phlebotomy. Malabsorption of food iron was less marked after PCV and SV + P than in patients after gastric resection, and it is concluded that there may be no need for a general prophylactic iron supplementation in patients operated on with PCV and SV + P.
Adult↗
Dietary heme iron absorption. A discussion of possible mechanisms for the absorption-promoting effect of meat and for the regulation of iron absorption.
Two main findings are reported. 1) The absorption of heme iron from a composite meal was very little if at all influenced by the subject's iron status at doses in the usual physiological range, but at high doses of heme iron there was a strong correlation with the subject's iron status. A hypothesis is presented to explain the regulation of iron absorption, so as to account for the impact of the subject's iron status, which is always evident with non-heme iron absorption but occurred only at high doses with heme iron. 2) Meat enhanced the absorption of heme iron. A probable explantation for the influence of meat on the separate absorbing mechanisms is that meat may stimulate the digestion of food, so that iron in either form is more efficiently released and made available for absorption.
Absorption↗
An analysis of factors leading to a reduction in iron deficiency in Swedish women.
The prevalence of iron deficiency anaemia among Swedish women of child-bearing age has fallen markedly since the mid-1960s. At that time, population studies in Göteborg and Uppsala showed that iron deficiency anaemia was present in about 25-30% of women. Later, in population studies in Göteborg in 1968-69 and 1974-75, the prevalence in the same age group was found to have fallen to 6-7%. Several factors may explain the improved iron status. The level of iron fortification of flour was increased from 30 mg/kg of flour in 1943 to 65 mg in 1970, this increase adjusting the iron intake to compensate for the lower energy requirement and expenditure of present-day living habits. There has also been a marked increase in the intake of iron tablets and of tablets containing ascorbic acid.An analysis of various factors indicates that the 20-25% improvement in iron status can be accounted for by increased use of oral contraceptives (3-4%), the impact of increased iron fortification (7-8%), the widespread use of ascorbic acid supplements (3%), and greater prescribing of iron tablets (10%).This analysis of the factors leading to the marked reduction in the prevalence of iron deficiency anaemia among Swedish women may be useful to public health planners in other countries with similar problems. Our results indicate that several factors need to be considered when planning controlled field trials and evaluating the results obtained. The methods used to analyse the impact of different factors on the reduction in iron deficiency can also be used to predict the effects of various public health measures on the iron status of a population.
Adolescent↗
Anthropometric data in middle-aged women. The population study of women in Göteborg 1968-1969.
Body weight, body height, skinfolds, circumferences and weight indices in a population sample of 1462 women in ages between 38 and 60 years are presented. Significant age differences were noted. High correlations (r) were found between body weight and triceps and subscapular skinfolds (0.62 and 0.72 respectively) and between body weight and arm, waist and buttock circumferences (0.75-0.88). Age differences were mostly noted between 46 and 50 years of age. After that age there was a comparatively greater increase of the waist circumference than of the buttock circumference, while triceps skinfold seemed to decrease after the age of 50 indicating an altered adipose tissue distribution from the extremities to the trunk with increasing age. When taking data from a previous study of body weight in the same population of women into consideration it seems that the age differences in body weight found in cross-sectional study like the present one may to a large extent depend on differences between different cohorts studied.
Adult↗
Estimation of available dietary iron.
Dietary iron requirements are dependent on the amount and availability of food iron ingested. On the basis of recent studies of food iron absorption employing extrinsic tag techniques, the availability of heme iron has been defined and estimates of the availability of nonheme iron based on the amounts of enhancing substances appear possible. A model has been developed whereby the availability of iron in a given meal may be estimated. Calculations are made on a meal basis of 1) the amount of heme iron and its availability, and 2) the amount of nonheme iron and its availability as influenced by the meal's content of enhancing factors. Examples of these calculations are provided.
Absorption↗
Iron absorption from South-East Asian diets and the effect of iron fortification.
The increase in iron absorption was measured when different amounts of ferrous sulphate were added to rice-based South-East Asian meals. The study comprised 158 subjects--118 women and 40 men. Iron fortification of simple meals composed of rice, boiled vegetables, and a curry to a level of 5 mg of iron per meal increased the absorption by about 0.2 to 0.3 mg of iron per meal. The additionof fish to such a meal doubled the absorption increase at a fortification level of 5 mg per meal. This absorption increase was about the same as obtained with composite western-type meals containing fish or meat. The results indicate that iron fortification programs may be effective in countries with rice-based diets provided that there is a suitable vehicle available for fortification.
Absorption↗
Absorption from iron tablets given with different types of meals.
The absorption of iron from tablets given with 5 types of meals was studied in 153 subjects. The meals were: a hamburger meal with beans and potatoes, a simple breakfast meal, a Latin American meal composed of black beans, rice and maize and two Southeast Asian meals composed of rice, vegetables and spices served with and without fish. The groups were directly compared by relating the absorption from the iron tablets to the absorption from a standardized reference dose of iron given on an empty stomach. The composition of meals with respect to content of meat or fish or the presence of large amounts of phytates seemed to have no influence on the absorption of iron from tablets. The absorption from iron tablets was about 40% higher when they were given with rice meals than when they were given with the other meals studied. The average decrease in absorption by meals was about 50-60% based on a comparison when tablets were given on an empty stomach. When tablets from which the iron was released more slowly were used, the absorption increased by about 30% except when they were given with rice meals, where the absorption was unchanged. The differences among the meals in their effect on the absorption of iron from tablets thus disappeared when the slow-release tablets were given.
Administration, Oral↗
The population study of women in Göteborg 1974--1975--the second phase of a longitudinal study. General design, purpose and sampling results.
A study of a population sample of women in Göteborg aged 38--60 years was carried out in 1968--1969. This population sample has been re-studied during the years 1974--1975. Altogether 1302 women participated in this second study, which means 89.1% of those studied in 1968--1969 and 80.3% of those initially sampled. Twenty-six women had died during the interval between the two studies, more than half of them from neoplastic disease. Information is given about those who had moved or were inaccessible at the time of the second study or who refused to participate. The performance of the examination is described and research projects are outlined.
Adult↗