These requirements are therefore very high, especially in relation to body size and . The fortification of cereal products with iron and ascorbic acid is important in .. is the fact that there are still reagent kits on the market for determining serum. Ann N Y Acad Sci. ; Interaction of vitamin C and iron. Lynch SR, Cook JD. Food iron is absorbed by the intestinal mucosa from two separate. Iron deficiency is a common health problem worldwide. Ferrous fumarate (a form of iron) is often added to foods in an effort to prevent iron deficiency. Vitamin C.
One of the most important of these factors is inadequate iron intake, especially heme iron, due to low intake of foods derived from animals, i.
The largest proportions were observed in developing countries. In children under 5 years, prevalence rates of During the first 6 months of life, exclusive maternal breastfeeding meets the basic iron requirements of fullterm children. After this period, even with the excellent bioavailability of iron in human milk, it is necessary to offer complementary foodstuffs that are rich in this micronutrient. The authors report that an increased intake of cow's milk, whose iron content is reduced and has low bioavailability, can reduce the total quantity of iron contained in the diet or substitute other possible sources of this nutrient.
Modified milk, enriched with iron, however, reduces the chances of anemia by increasing the density of iron in the milk. Positive and significant associations were observed both in a model that corrected for demographic and socioeconomic variables and also in one that made further corrections for the iron density in the diet.
The authors suggested two mechanisms to explain the negative influence of cow's milk intake on hemoglobin concentration: Iron supply is most affected when cow's milk is introduced early and becomes the primary food source, substituting or complementing savory foods.
Studies have shown just how early cow's milk is being introduced and that the volume of milk consumed reduces as children get older. As a result children receive a progressively greater iron supply, probably as a result of the introduction of other foods that are not milk-based. In addition to the low content and bioavailability of iron, ingestion of cow's milk can interfere in the absorption of iron from other foodstuffs and can provoke occult blood loss in feces.
It is important to be aware of, not just total iron intake, but also the composition of feeds and the presence of dietary components that could inhibit or stimulate iron uptake. In response to the high level of cow's milk intake in infant nutrition and the negative impact of iron deficiency anemia on children's development, the purpose of the present study is to review certain aspects of the consumption of this foodstuff that are related to this severe nutritional problem.
The functions of iron in the body Within the body, iron is linked with two categories of components: The functional components are hemoglobin and myoglobin, in lower quantities within body tissues, and several other proteins that are active in the transport, storage and utilization of oxygen.
Iron also participates in a variety of biochemical processes, including the transport of electrons in the mitochondria, metabolism of catecholamines and DNA synthesis. When dietary iron supply is inadequate, the element is mobilized from the storage components to maintain the production of hemoglobin and other iron compounds that perform metabolic functions.
It is probable that functional alterations do not take place while this production is not prejudiced. Nevertheless, subclinical iron deficiencies can be detrimental to health at all stages of life because they cause oxidative metabolism disorders and are associated with altered oxidative performance, muscular function, physical activity, productivity at work or school, mental acuity and the capacity to concentrate.
Furthermore, there can be alterations to thermogenesis, the skin, nails and mucosas, in addition to reduced immunoresponse, which in turn increases morbidity due to infectious diseases. Furthermore, these children have faster postnatal growth rates than children born full term, which means that they use up their reserves earlier and consequently their iron requirements are greater. There is normally a reduction in iron reserves in the liver during the first 6 months of life, 18 and the absence of or partial or total substitution of maternal breastmilk by other types of milk contributes to the appearance of anemia.
Foods used for weaning with low bioavailability can also interfere in the absorption of the iron that is present in maternal milk. Requirements are first defined as the iron that must be absorbed and then converted into estimates of dietary iron requirements, taking bioavailability into account. Low energy intake very often means that the requirements for certain nutrients are not fully attained.
Cow's milk consumption and iron deficiency anemia in children
The density of bioavailable iron is defined as the quantity of iron absorbed in milligrams from a meal for every 1, kcal. In developing countries, the majority of complementary foods offered to children are low or intermediate bioavailability foods. Whey proteins are more easily digested than casein, which demands that more hydrochloric acid is secreted so that stomach pH is sufficient for it to be digested by pepsin. The principal sugar present in milk human and cow's milk and in infant formulae is lactose and its functions are: In terms of lipids, there are significant differences in fatty acid composition: The larger the chain and more saturated the fatty acid is, the lower is its absorption.
Cow's milk is low in linoleic acid and vitamin E and contains excessive quantities of sodium, potassium and proteins. Cow's milk also offers low levels of vitamin C, considered a factor that stimulates iron absorption, and high levels of calcium and phosphorous, factors that inhibit iron absorption.
The many different types of milk available on the market are products based on cow's milk in natura, and their composition may have been modified by fortification or reduction of nutrients e.
Although it appears to be a practical and economic option, cow's milk, either whole milk or diluted with water, with flour or sugar added, is not indicated for children less than 12 months old because of the innumerable adverse effects it can have on their health.
Some of the most common clinical manifestations include gastrointestinal, respiratory, cutaneous and anaphylactic symptoms. Furthermore, since cow's milk is the most common food in the diet during weaning and is often used in detriment to other foods that are iron sources, substituting or complementing a savory meal, may encourage the development of iron deficiency anemia.
Interaction of vitamin C and iron.
Some dietary factors that increase this bioavailability are meat beef, fish, poultry and liver and ascorbic acid. The mechanism by which meat stimulates iron absorption is not yet entirely understood. There is evidence that it acts to reduce the inhibitory effects of polyphenols and phytates on the absorption of nonheme iron and increases the bioavailability of heme iron, even though these types of iron have different absorption mechanisms.
Vitamin C can also affect the transport and storage of iron in the organism, since individuals who are deficient in this vitamin can exhibit defects in the liberation of iron from endothelial cells. Therefore, the inclusion of fruit and vegetables rich in vitamin C in the diet makes dietary iron more available. On this list are the phytates present in cereals, the oxalic acid present in leafy vegetables, the polyphenols in high concentrations in coffee and tea and phosvitin, which is a protein found in egg yolks, bonded to iron.
Excessive consumption of zinc or calcium, especially in the form of supplements, can interfere in the utilization of iron if consumed simultaneously. One possible explanation is that calcium and iron compete for bonds with substances that are important to the absorption route, i.
Anemia prevalence rates are high in populations affected by vitamin A deficiency.
Iron Deficiency Anemia: A Guide to Oral Iron Supplements
It appears to be involved in the pathogenesis of anemia through several different biological mechanisms: Animal tissue beef, pork, liver, chicken and fish increases the absorption of this micronutrient. On the other hand, casein and whey proteins from cow's milk account for the greater proportion of the protein present in the majority of infant formulae and foods and have a negative influence on iron uptake, particularly if the increased requirements of children that result from their accentuated growth are taken into account.Vitamin C and iron absorption
A study undertaken by Hurrel et al. When these proteins were tested intact in vitro, the majority of iron did not pass the dialysis membrane, indicating that it had formed compounds that were insoluble or too large to pass through the membrane's pores. The authors argued that cysteine is the only amino acid that has been demonstrated to increase iron absorption and neither casein nor whey proteins have large quantities of this amino acid. Cow's milk has approximately four times more calcium than human milk, which can contribute to low iron absorption.
This maximum inhibitory effect is achieved with an approximate intake of mg of calcium, which is the equivalent to that contained in one glass of milk or a piece of cheese, for which reason the authors recommend that these should not be consumed regularly at the main iron-providing meals, particularly by those who have increased iron requirements children, adolescents and women of fertile age.
The earlier that cow's milk is introduced, the greater the chance of iron deficiency. The results suggested that the intestinal blood loss provoked by exposure to cow's milk is a characteristic phenomenon among younger children that gradually disappears during the second half of their first year of life and does not cause clinical repercussions.
The Relationship Between Iron and Vitamin C - Fergon
Systemic signs and symptoms are generally absent, with the exception of pain during defecation and eczema, which may be presented by some patients. Cow's milk protein allergy can induce a syndrome characterized by chronic diarrhea with steatorrhealesions of the jejunal mucosa and weight loss, similar to celiac disease.
Anemia, hypoprothrombinemia and vitamin K deficiency coagulopathy can be observed in laboratory tests. Histopathological studies of the jejunal mucosa also reversal that atrophy of the intestinal villa with hypertrophy of the crypts is also present to varying degrees.
Often, such parasitosis affects nutritional status at a several different stages of the lifecycle, through reductions in nutritional intake, maldigestion and malabsorption. Ancylostomiasis, defined as human infestation by two nematodes of the ancylostomidae family Ancilostoma duodenalis and Necator americanustrichuriasis Trichuris trichiura and schistosomiasis Schistosoma mansoni can provoke chronic blood losses.
This intestinal blood loss reaches an average of 2 ml or 1 mg of iron daily when Necator americanus is present and twice this when the cause is Ancilostoma duodenalis, with a third of this iron being reabsorbed in the gastrointestinal tract. Studies demonstrate a direct relationship between the intensity of the infection, blood losses and anemia. Gastrointestinal upset is a common side effect that limits patient compliance with iron therapy. Proposed strategies to avoid this include reducing the dose, administering iron during mealtimes, or opting for enteric-coated preparations or a polysaccharide-iron complex Niferex.
However, all these strategies impair iron absorption and may result in suboptimal clinical outcomes. Lastly, further investigation is needed in the areas of vitamin C co-administration and the optimal duration of iron therapy. Pathophysiology of iron homeostasis. National Institutes of Health: Office of Dietary Supplements.
Dietary supplement fact sheet: Accessed 9 November Iron deficiency and other hypoproliferative anemias. Brise H, Hallberg L. Absorbability of different iron compounds. Acta Med Scand Suppl ; Hemoglobin regeneration in severe iron-deficiency anemia. Individualized treatment for iron-deficiency anemia in adults.
Am Jour of Med ; Are we giving too much iron? Low-dose iron therapy is effective in octogenarians. Am J of Med ; Tolerability of different oral iron supplements: Influence of meals on iron absorption in oral iron therapy.
Acta Med Scanda Suppl ; Side-effects of oral iron therapy: Bioavailability of iron in oral ferrous sulfate preparations in healthy volunteers. Canadian Med Assoc Jour ; 6: Comparison of a combination ferrous fumarate product and a polysaccharide iron complex as oral treatments of iron deficiency anemia: Effect of ascorbic acid on iron absorption.
Disorders of iron homeostasis: