Trace elements whose requirements are increased during gravidity include iron, iodine, copper, selenium and zinc. In addition to these trace elements, pregnant women should also pay attention to an adequate dietary intake of chromium, fluorine, manganese, molybdenum, as well as tin. The daily requirement of these trace elements is not increased during pregnancy. Nevertheless, they must not be missing in a balanced and adequate diet, as micronutrients (vital substances) are also of important significance for the growth and development of the child and the health and vitality of the mother [2.2. ].The intake of these trace elements ultimately serves to ensure reserves, with fluorine in particular providing caries and periodontosis prophylaxis. The intake of 1 milligram of fluoride per day is recommended during pregnancy [2.2]. Intake values for the daily requirement of pregnant women (based on DGE):
| Trace elements | Dosage |
| Chromium | 30-100 µg |
| Iron | 30 mg |
| Fluorine | 3.3 mg |
| Iodine* | 230 µg |
| Copper | 1.0-1.5 mg |
| Manganese | 2.0-5.0 mg |
| Molybdenum | 50-100 µg |
| Selenium | 60 µg |
| Tin | 3.6 mg |
| Zinc* * | 9.0-11 mg |
* Supplementation of 150 µg/day required* * Pregnant: 1st trimester (third trimester) or 2nd and 3rd trimestersDGE: German Society for Nutrition e. V.
Iron
Function of iron
- Iron is bound to proteins – hemoglobin, myoglobin, cytochromes – to be bioavailable to the organism despite its poor solubility
- Occurrence as heme iron and non-heme iron.
Hemiron compounds – 2-valent iron.
- Iron is as a component of hemoglobin is responsible for oxygen transport
- Iron as a component of myoglobin contributes to the formation and storage of oxygen
- Iron as a component of cytochromes is important for electron transport of the respiratory chain
Sources: Occurrence in predominantly animal foods – meat products, liver and fish.
Non-heme iron compounds – trivalent iron.
- Antioxidant effect
- Oxygen transfer
- Detoxification processes
- Energy production, as non-heme iron proteins participate in energy production in the mitochondria
- Production of hormones and neurotransmitters
- Collagen synthesis, as iron is essential for the regeneration of bone, cartilage and connective tissue
- Transferrin as a carrier protein of iron protects against damage by free radicals and lipid peroxidation, protection against atherosclerosis (arteriosclerosis, hardening of the arteries).
Sources: Occurrence in predominantly plant foods – fruits, vegetables and cereals, lentils, white beans, wheat flour, parsley, whole grain and soy products, brewer’s yeast Hemiron has better bioavailability than non-heme iron at 15-35% because it is highly soluble at the pH values that prevail in the small intestine Only in animal foods – beef, pork, turkey, liver, and fish – is some iron present as heme iron, which increases the bioavailability of iron. In addition, the iron content in meat is relatively high.By eating meat and plant foods at the same time, the absorption rate of non-heme iron from the plant diet can be doubled. This is due to the low molecular weight complexing agents contained in meat, including animal proteins, which are of higher quality than plant proteins due to the high number of valuable amino acids and thus favor the absorption of iron. In a meat-free diet, therefore, more iron must be ingested to meet the demand [4.2. ].The absorption of iron from food is further increased by gastroferrin – secretion of the gastric mucosa, vitamin C, fermented foods, polyoxicarboxylic acids in fruits and vegetables, and other organic acids – citric acid. These substances form a highly soluble complex with iron. In contrast, the bioavailability of non-heme iron from plant foods is much lower. The iron from plant sources is rarely absorbed more than 5%.Plant foods with a high iron content are mainly whole grains, legumes, some vegetables, brewer’s yeast and parsley. The bioavailability of non-heme plant iron can be significantly increased by offering vitamin C at the same time. 75 milligrams of vitamin C, for example in 150 grams of spinach or kohlrabi, increase the bioavailability of non-heme iron by a factor of 3 to 4, since vitamin C can reduce trivalent iron to the more absorbable bivalent iron.Phytic acid (phytates) in cereals, corn, rice, and whole grain and soy products, tannins in coffee and tea, polyphenols in black tea, and calcium in milk and milk products have a strong inhibitory effect on iron absorption. These substances form a non-absorbable complex with iron and therefore block its absorption. The iron requirement is very high during pregnancy due to the additional iron demand of the fetus, the rapid tissue proliferation and the increase in blood formation and should be covered by a balanced and varied diet. It is therefore recommended that iron-rich plant foods, such as whole grain cereals or certain vegetables – broccoli, peas and others – be consumed in combination with animal products to double the rate of absorption of non-heme iron from plant foods. Pregnant women with little or no meat consumption due to vegetarian, vegan, or macrobiotic diets need to pay particular attention to their iron intake to meet their needs. By determining transferrin and ferritin levels, respectively, it is possible to monitor adequate iron intake. By determining the ferritin serum level, it is possible to control an adequate iron intake. Ferritin is an endogenous carrier protein of iron, the concentrations of which shift as a result of altered estrogen metabolismuś. If low ferritin values can be detected, the body has only low iron concentrations in the blood (iron deficiency or iron resorption disorder) [2.2. ].Note!Iron is better absorbed by the body if you take a food containing vitamin C – such as orange juice – with it; tea and coffee, on the other hand, inhibit the absorption of iron. Iron is also discussed as a prooxidant in connection with the development of cardiovascular diseases – such as coronary artery disease resulting in a heart attack – and neurodegenerative diseases – such as Alzheimer’s disease or Parkinson’s disease – and as a promoter of cancer. The underlying mechanism is thought to be that iron promotes oxidative stress via its key catalytic function in the formation of cytotoxic oxygen and hydroxyl radicals, for example in the course of Fenton and Haber-Weiss reactions.Individuals suffering from hemochromatosis – “iron storage disease” – for example, have an increased risk of hepatocellular carcinoma. In addition, a study from the USA showed that an elevated serum iron level is associated with an increased risk of cancer.Caution!Before iron substitution therapy, it is always necessary to determine the serum ferritin level.Only if a pathological finding is proven, iron therapy may be initiated by the doctor!No food supplement – except for pregnant women and nursing mothers – should therefore contain iron in the interests of consumer protection.
Iodine
Function of iodine
- The most important function is the synthesis of thyroid hormones, which regulate metabolic activity
- Antioxidant effect, scavenger of free radicals.
- Activating effect on certain immune functions
- Prevents inflammatory-degenerative diseases
Sources: Good sources of iodine are seawater products, such as raw fish – sushi, sea fish -, seafood and sea tank; iodine-rich mineral waters, milk, eggs if the supplying animals are fed appropriately, and foods fortified with iodized salt Pregnancy places a significant additional functional burden on the mother’s thyroid gland. To meet the increased demand associated with an increased basal metabolic rate during pregnancy, the thyroid gland must produce increased amounts of thyroid hormones. In addition, as a result of the increased filtration rate of the kidney during pregnancy, there is an increased excretion of iodine in the urine, which worsens the iodine supply to the thyroid gland. As a result, iodine losses must be compensated for by targeted additional iodine intake [2.2].Women during pregnancy who follow a vegan or macrobiotic diet or do not use iodized table salt when preparing their food are at high risk of insufficient iodine supply. The thyroid function of the mother and especially the development of the fetuś are at considerable risk under such circumstances Even a mild iodine deficiency has an unfavorable effect on the brain development of the child. In this context, an adequate iodine supply is crucial for cognitive development, especially in the first trimester (third trimester of pregnancy). Therefore, an additional iodine intake is recommended for all pregnant women. This also applies to women with autoimmune thyroid diseases such as Hashimoto’s thyroiditis or Graves’ disease in remission (temporary or permanent reduction of disease symptoms, but without achieving recovery). In addition, the iodine supply in Germany is insufficient, which makes iodine substitution of the mother during pregnancy as also necessary. With the help of a prophylactic iodine supplementation a healthy development as well as an undisturbed growth of the child can be ensured.The Federal Institute for Risk Assessment (BfR) recommends for food supplementation not to exceed the maximum value of 100 µg iodine per day.Exception: The Federal Institute for Risk Assessment recommends 100-150 µg iodine per day in tablet form for pregnant and nursing women. Note: Less than 150 µg of iodine per day per day increases the risk of preeclampsia and fetal growth retardation:
- At 75 µg of iodine per day, the risk of preeclampsia (EPH-gestosis or proteinuric hypertension/pregnancy hypertension) increased by 14% compared with the reference group (100 µg daily); at 50 µg, by 40%.
- Preterm birth also occurred more frequently among (adjusted odds ratio, aOR: 1.10 and 1.28, respectively).
Copper
Function of copper
- Component of various enzymes
- Antioxidant effect, detoxification free radicals, immunostimulant, anti-inflammatory.
- Important component of the endogenous antioxidant cell protection of the cell membrane, promotes cell growth.
- Promotes iron absorption
- Component of the respiratory chain, cellular oxygen utilization, serves for energy production.
- Protection of amino acids
- Melanin and connective tissue synthesis
Sources: Rich in copper are offal, fish, cereal products, shellfish, nuts, chocolate, cocoa, coffee, tea and green vegetables Important note!The data available for the Federal Republic of Germany on the intake of copper indicate that in otherwise healthy individuals is not expected to have an insufficient supply of the trace element copper (supply category 3). The addition of copper to food supplements is therefore not recommended. In addition, a study from the USA showed that elevated serum copper levels are associated with an increased risk of cancer. Copper is found in the diet in cereal products, offal (liver and kidneys of ruminants may have particularly high copper levels), fish, shellfish, legumes, nuts, cocoa, chocolate, coffee, tea, and some green vegetables.
Selenium
Function of selenium
- Causes increase in activity of the main antioxidant enzyme – glutathione peroxidase.
- Antioxidant action via glutathione peroxidases to maintain the balance of oxidants and antioxidants in organism.
- Stimulates the production of antibodies
- Glutathione peroxidases are responsible for the conversion of harmful hydrogen and lipid peroxides to water and prevent production of oxygen radicals
- Selenium affects activation and deactivation of thyroid hormones via the selenium-dependent enzymes – deiodases.
- Through the glutathione peroxidases, selenium protects macromolecules – carbohydrates, proteins, fats – as well as cell membranes and components, working closely with antioxidant vitamins A, C, E and some B vitamins
- Some selenium proteins have immunomodulatory and membrane stabilizing effects.
- Forms with heavy metals such as lead, cadmium and mercury poorly soluble and therefore difficult to absorb non-toxic selenite protein complexes.
Sources: Good sources of selenium are sea fish, kidney, liver, red meat, fish, eggs, asparagus and lentils; the selenium content in cereals depends on the selenium content of the soil Pregnant women have no increased selenium requirements.However, if women eat a vegan diet during pregnancy, they will not reach sufficient selenium levels in our regions without substitution and are at high risk of deficiency. In particular, Germany, Switzerland and Austria are selenium deficient areas, as agricultural soils contain too little of the trace element due to fertilizers and acid rain, and animal feed is insufficiently enriched with selenium. Selenium is not needed for plant growth, making cultivated grain virtually selenium-free. Bioavailability is further reduced by heavy metals in the soil, with which selenium forms an insoluble complex. If selenium is substituted together with physiological doses of vitamin E and vitamin C, this increases the absorption rate
Zinc
Function of ZincInvolved in many anabolic and catabolic enzyme reactions, either as a cofactor or as an essential protein component in enzymatic reactions, thus fulfilling functions such as.
- Stabilization of the structures of DNA, RNA and ribosomes, protects them from oxidation.
- Large-scale wound healing and regeneration of burns.
- Carbohydrate, fat and protein metabolism.
- Alcohol degradation
- Affects the visual process, as responsible for the conversion of retinol to retinal.
- Involved in the metabolism of thyroid hormones, growth hormones, insulin and prostaglandins; affects development and maturation of male sex organs and spermatogenesis.
- Antioxidant effect – protects cells from radical attacks.
- Immunomodulation – activity of T-helper cells, T-killer cells and natural killer cells depends on adequate zinc supply.
- Essential for the normal functioning of skin, hair and nails; involved in the structural strength of nails and hair.
Sources: Very rich in zinc are oysters, wheat germ, muscle meat – beef, veal, pork, poultry; offal – liver, kidneys, heart; lower zinc levels have eggs, milk, cheese, fish, carrots, whole grain bread, fruits, green vegetables, legumes and fats The bioavailability of zinc is significantly better from animal products compared to vegetable. For example, zinc absorption from beef is 3 to 4 times higher than from cereals. The reason for this is animal protein, which is of higher quality than plant protein and, as with iron, increases bioavailability. Amino acids, such as histidine, methionine and cystidine in protein, are low-molecular complexing agents, which explains the good absorption rate of animal protein. Animal protein also has a corresponding resorption-promoting effect with regard to zinc absorption from plant foods. Therefore, it is advisable to eat meat products combined with plant foods in one meal and not to completely avoid animal protein.Furthermore, the organo-zinc compounds found in animal foods – chelate, orotate, gluconate and protein hydrolysate – are better absorbed by the human organism than the inorganic zinc salts found in plant foods. In contrast, excessive calcium, copper, iron and phosphate intake, phytic acid from cereals, corn and rice, dietary fiber and heavy metals reduce zinc absorption due to the non-absorbable complex formation [4.2. ].If pregnant women eat a predominantly vegetarian diet, only about 10% of zinc is absorbed because the animal, high-quality protein is completely omitted. In this way, the risk of zinc deficiency increases [4.2. ].Zinc consumption is increased beginning in the second month of pregnancy and even more significantly thereafter due to rapid tissue proliferation – new placental tissue formation -, the increase in blood formation and the mother’s increased metabolic rate [316.Due to this, zinc substitution is necessary. However, the trace element should be supplied in the form of chelate, orotate, gluconate, and protein hydrolysate, as these have better bioavailability than inorganic zinc sulfate. Taken on an empty stomach, zinc sulfate induces nausea in some people, and thus may exacerbate pregnancy-related nauseaTable – Need for trace elements
| Minerals and trace elements | Deficiency symptoms – effects on the mother | Deficiency symptoms – effects on the fetus or infant, respectively |
| Iron | Fever around 38 °C occurring between the 2nd and 6th day after delivery as a result of bacterial infections of the uterus – puerperal fever causes
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Formation of maternal anemia with hemoglobin levels below 11 g/dL increases the risk for
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| Zinc |
Metabolic disorders, such as.
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Increased risk for
Low concentrations of zinc in plasma and leukocytes (white blood cells) cause
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| Iodine | Thyroid gland, hypothalamus and pituitary gland attempt to compensate for iodine deficiency
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Iodine deficiency causes
In newborns, iodine deficiency leads to.
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| Selenium |
Increased risk of
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| Copper |
|
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