Minerals whose requirements are increased during pregnancy include calcium, magnesium and phosphorus.In addition to these minerals, pregnant women should also ensure an adequate dietary intake of sodium, potassium and chloride. The daily requirement of these minerals is not increased during pregnancy. Nevertheless, they should not be missing in a balanced and adequate diet, since vital substances (micronutrients) are also of important significance for the growth and development of the child and the health and vitality of the mother. The intake of these minerals ultimately serves to ensure reserves.Too little sodium and fluid intake prevents the physiologically necessary increase in extracellular fluid. Too little increase in plasma volume can result in reduced blood flow in the placenta, reduced cardiac volume, and increased vascular resistance. In this case, safe supply of the fetuś can no longer be ensured. Consequently, adequate fluid intake – 40 milliliters per kilogram of body weight – as well as sodium intake – 2-3 grams of table salt per day – is essential. Intake values for the daily requirement of pregnant women (based on the DGE):
| Minerals | Dosage |
| Calcium | 1,000 mg |
| Chloride | 2,300 mg |
| Potassium | 4,000 mg |
| Magnesium | 310 mg |
| Sodium | 1,500 mg* |
* 2-3 grams in the form of table saltDGE: German Society for Nutrition e. V.
Calcium
Function of calcium
- Bone structure as well as strength and teeth
- Affects nervous excitation formation as well as nerve conduction velocity.
- Control of conduction in nerves and muscles.
- Stimulation of the contraction of muscle cells
- Involved in fluid transport across cell membranes
- Ensuring cell metabolism, cell division and stabilization of cell membranes.
- Release of hormones and neurotransmitters.
- Activation factor in blood clotting
Sources
- Calcium-rich foods include milk and dairy products – half a liter of milk contains about 600 mg of calcium – salmon, sardines, sesame seeds, soybeans, legumes, nuts, whole grains, wheat germ, oatmeal, green vegetables and parsley
- Most plant foods are low in calcium. In addition, the bioavailability of calcium from plant foods is often inhibited by their high levels of phytic acid (phytates), oxalate and dietary fiber
During pregnancy, calcium absorption is increased and calcium excretion is decreased. The storage of this mineral in the skeleton increases more than twice, especially in the last weeks of pregnancy. Nevertheless, calcium intake during pregnancy must not be underestimated and must be subject to an increase due to the increased demand. The increase in demand increases steadily with in the course of pregnancy. Pregnant women often experience deficiencies. The reasons for this lie in the respective diets. For example, if too little milk and dairy products or calcium-rich mineral waters are consumed, the mother’s calcium reserves in the bones are mobilized to ensure the fetuś’s supply. As a result, osteoporosis may develop in the mother or aggravate an already existing osteoporosis. In the child, high calcium deficiencies in the mother can lead to a decrease in bone density [5.3]. In this case, the supplementary administration of calcium preparations proves to be sensible, since in this way sufficient calcium stores are built up in the mother, the bones do not have to be attacked as reserves and the health of the child is also ensured [5.2]. Foods and substances that inhibit calcium absorption are phosphates, chocolate, cocoa, nut nougat cream, tannic acid in coffee and black tea, alcohol, fat and phytic acid (phytates) in cereals. Such substances and foods should always be considered in the diet during pregnancy. In particular, pregnant women with lactose intolerance (lactose intolerance) have an increased need for calcium.Affected individuals are unable to break down lactose due to low concentrations of the enzyme lactase. Common symptoms include flatulence, diarrhea and cramp-like symptoms. For dietary treatment, lactose in particular must be avoided. Since lactose is found exclusively in milk and dairy products, complete avoidance can lead to calcium deficiencies and eventually calcium deficiency symptoms.Lactose promotes the absorption of minerals and protein in the intestine. In addition, lactose improves the absorption and utilization of animal as well as plant protein. Pregnant women with lactose intolerance must therefore make sure that they cover their increased needs with other calcium-rich foods – intake of certain types of cheese or appropriately treated milk. Calcium supplementation is also beneficial in such cases [2.2]. Additional calcium supplementation improves blood pressure and thus reduces the risk of gestosis [2.2]. If a pregnant woman has low vitamin D levels in addition to low calcium concentrations, this can lead to bone softening and bone deformities in the mother (osteomalacia). In the child, there is hyperparathyroidism – enlarged parathyroid tissue – and increased production of parathyroid hormones (hyperparathyroidism). The excess of parathyroid hormones in turn increases the calcium level in the child’s blood. In the worst case, hyperparathyroidism of the child results in hypercalcemic coma [2.2. ].To prevent such symptoms, it is useful to perform vitamin D substitution in addition to the administration of calcium supplements. Adequate vitamin D levels promote calcium absorption and the release of calcium from the skeleton. In addition, vitamin D reduces calcium excretion by the kidneys [5.2]. Since magnesium is responsible for neuromuscular excitation conduction and transmission in addition to calcium, the two minerals interact closely. In the case of magnesium deficiency, the calcium level in the blood is reduced. Therefore, it is important to always substitute calcium together with magnesium in a 3:1 ratio. Excessive calcium intake, on the other hand, can interfere with the absorption of iron, zinc, and other essential vital substances (micronutrients) and further lead to increased magnesium and calcium excretion in the urine (hypercalciuria), as well as impair kidney function.
Magnesium
Function of magnesium
- Energy production and supply
- As an enzyme activator, magnesium plays an important role in all ATP-dependent reactions
- Oxidative degradation of energy-providing carbohydrates, proteins, fats and glucose.
- Neuromuscular excitation conduction and transmission.
- Decrease in the excitability of muscles and nerves.
- Affects nerve excitation as well as nerve conduction velocity.
- Acts closely with calcium
- Important component of the skeletal system – building bones and teeth.
- Important for osseous and muscular function
- Acts to lower blood pressure by magnesium dilates the coronary and peripheral arteries
- Ensures biosynthesis of DNA and RNA, protein biosynthesis (new protein formation), lipolysis, energy-dependent membrane transport and glucose breakdown.
- Decreases clotting ability of the blood
- Lowers serum cholesterol levels
Sources: Found in whole seeds, nuts, milk, potatoes, vegetables, soft fruits, bananas, tea and unground cereals The increased magnesium requirement is due both to the growth of the fetuś and placenta, and to a 25% increase in magnesium excretion by pregnant women through the kidneys. Adequate maintenance of magnesium concentration is not guaranteed with today’s relatively poor dietary magnesium supply. Due to the magnesium depletion of agricultural soils as a result of the use of artificial fertilizers, magnesium concentrations in plant as well as animal foods have decreased. The increased protein and fat-rich diet in today’s society and the resulting increased protein metabolism, make it difficult to absorb magnesium. For these reasons, pregnant women in particular have high magnesium deficiencies.To prevent a magnesium deficiency, magnesium supplementation is recommended from early pregnancy until birth.Magnesium should be substituted together with calcium – in the optimal ratio of calcium to magnesium 3:1. Premature supplementation prevents preterm labor, seizures – nocturnal calf cramps, uterine contractions, pregnancy-induced hypertension, and constipation, which is more common during pregnancy.
Phosphorus
Function of phosphorus
- Bone formation
- As a component of energy-rich ATP, it is involved in all energy-consuming processes and ensures muscle and brain activity, all growth processes, sensory perception and body heat, among other things
- Cofactor for the function of most B vitamins involved in intracellular energy metabolism.
- Increase energy metabolism, as a component of high-energy KrP as well as in the process of glycolysis.
- Guarantees the reactivity of various enzymes, maintaining the acid-base balance and pH – phosphate buffer system.
- Component of numerous enzymes, nucleic acids and biomembranes.
Sources: Phosphate is found in virtually all plant and animal foods, main sources are protein-rich foods – meat, poultry, fish, milk -, as well as brewer’s yeast, soybeans, legumes, nuts, wheat germ and cereals Phosphorus, like calcium, is an important bone mineral. Calcium and phosphate metabolism are closely linked via parathyroid hormone, which promotes phosphate excretion. Since phosphate ions carry calcium as a cation during renal excretion, parathyroid hormone also indirectly influences calcium excretion. Thus, when phosphate is released from the bones, calcium is always mobilized as well, since it is stored in the skeletal system in the form of phosphate salts. Phosphorus and calcium are thus closely linked. During pregnancy, substitution is not necessary because phosphorus is present in almost all foods. Excessive phosphate intake increases calcium excretion and decreases calcium absorption [5.2. ].Phosphate deficiency is extremely rare, since the mineral is abundantly supplied in the diet and phosphate can be mobilized from the bone if necessary. In particular, in some metabolic diseases – phosphate diabetes, hyperparathyroidism – high amounts of the mineral are excreted, which can cause deficiency symptoms [5.2. ].Table – Requirements of minerals.
| Minerals and trace elements | Deficiency symptoms – effects on the mother | Deficiency symptoms – effects on the fetus or infant, respectively |
| Calcium | Demineralization of the skeletal system increases the risk of
Increased risk of
|
Symptoms of rickets
Additional vitamin D deficiency leads to
|
| Magnesium |
Increased excitability of muscles and nerves leads to.
Increased risk of
|
Increased risk of
|
| Phosphorus |
|
|