Human Biochemistry, Volume 2 - Murray R. 1993

Special Topics
Nutrition, Digestion, and Absorption
Dietary Guidelines

All dietary requirements should aim to prevent nutritional deficiency diseases and promote overall health. Failure to meet these requirements is almost invariably rooted in ignorance or economic poverty. On the other hand, certain common diseases are linked to the excessive consumption of specific foods. Obesity typically reflects an excess intake of energy-rich foods and is frequently associated with The Development of non-Insulin-dependent Diabetes Mellitus. Atherosclerosis and CORONARY Heart DISEASE are generally caused by diets high in total and saturated fat. The development of breast, colon, and prostate Cancer correlates with a high fat intake, while cerebrovascular disease and Hypertension are associated with the consumption of large amounts of salt.

Committees have been established in many countries worldwide to formulate guidelines for improving the human diet. These recommendations can be summarized as follows: 1) in cases of overweight, total energy intake should be reduced; 2) the diet should contain fewer fats and more CARBOHYDRATES; 3) the majority of carbohydrates should be consumed as complex carbohydrates and a smaller proportion as sugars; 4) more polyunsaturated fats and fewer saturated fats should be consumed; 5) Cholesterol and salt intake should be kept to a minimum; 6) The amount of dietary fiber in the diet must be increased.

Class="center">Table 53.8. Major macroelements. Main properties

Elements

Functions

METABOLISM 1)

Deficiency disease or symptoms

Toxicity disease or symptoms2)

Sources 3)

Calcium

Component of bones, Teeth; regulation of nerve and Muscle Function

Absorption requires a calcium-binding protein. Regulated by vitamin D, parathyroid hormone, Calcitonin, etc.

Children: Rickets

Adults:

Osteomalacia. May play a role in the development of Osteoporosis

Occurs with excessive absorption due to vitamin D hypervitaminosis or hypercalcemia secondary to hyperparathyroidism, as well as in idiopathic hypercalcemia

Dairy products, legumes, green leafy vegetables

Phosphorus

Component of bones, teeth, ATP, phosphorylated metabolic intermediates, Nucleic Acids

Regulation of absorption unknown (vitamin D?). Serum levels regulated by renal reabsorption

Children: rickets

Adults: osteomalacia

Low ratio of

Ca2+: Pinorg

in serum stimulates the development of secondary hyperparathyroidism; bone resorption may occur

Phosphate food additives

Sodium

Major extracellular cation. Regulates plasma volume, acid-base balance, nerve and muscle function, Na+/K+-ATPase

Regulated by

aldosterone

Unknown on a normal diet; occurs during trauma or disease

Hypertension (in predisposed individuals)

Table salt

Potassium

Major intracellular cation; nerve and muscle function, Na+/K+-ATPase

Also regulated by aldosterone

Develops secondarily to disease, trauma, or diuretic therapy; muscle weakness, paralysis, mental confusion

Cardiac arrest, small bowel ulcers

Chloride

Fluid and electrolyte balance; component of gastric juice

Infants receiving salt-free diets. Occurs in connection with vomiting, diuretic therapy, Kidney disease

Table salt

Magnesium

Component of bones, teeth; enzyme cofactor (Kinases, etc.)

Develops with malabsorption, diarrhea, or alcoholism

Depression of

deep tendon Reflexes and Respiration

Green leafy vegetables (containing chlorophyll)

1) Carrier Proteins are generally required for the absorption of minerals. Absorption is rarely complete and is influenced by other dietary components and compounds present in food (e.g., oxalates and phytates, which chelate divalent cations). Specific proteins are also necessary for TRANSPORT AND STORAGE. Mineral excretion occurs via feces (unabsorbed minerals), urine, sweat, and Bile.

2) Excessive intake of minerals causes symptoms of toxicity. Unless otherwise specified, this implies nausea, diarrhea, and irritability.

3) Mineral Requirements are met by including adequate amounts of whole grains, legumes, green leafy vegetables, meat, and dairy products in the diet.





Last update: 06/08/2026

Editorial and Educational Adaptation: This material has been compiled based on the primary/original source text. The project team performed an editorial review, corrected technical inaccuracies, structured sections, and adapted the content for an educational format.

What was processed:

  • elimination of formatting defects (OCR errors, structural breaks, corrupted characters);
  • editorial organization of content;
  • standardization of terminology in accordance with academic sources;
  • verification of factual statements against the original source text.

All mentions of the author, publication year, and origin of the primary text have been preserved in accordance with the source.