Posted on 10 Oct 2009 23:38
Minerals are central to human nutrition and many are involved in uncountable biological functions. Minerals constitute only about four percent of the body's weight but their importance should not be overlooked, and it was the observance of minerals in the composition of the body's tissues and fluids that clued us in to their importance in human nutrition.
Certain minerals are found in greater abundance in the body and these minerals are referred to as macrominerals. Read more about them below or see our Youtube presentation.
There is as yet not one standard definition of what defines a macromineral (percentage of body weight, etc) but seven major minerals are accepted as macros, which are also referred to macronutrient elements. These are calcium, chloride, magnesium, phosphorus, potassium, sodium and sulfur.
The following table provides a sampling of their biological functions, deficiency symptoms and major food sources.
|Mineral||Functions||Defiency Symptoms||Food Sources (Order of Abundance)|
|Calcium||structural bone and teeth component, cellular processes, muscle contraction, blood clotting, enzyme activation||Rickets, osteomalasia, osteoporosis, tetany||milk, milk products, sardines, clams, oysters, turnip and mustard greens, broccolli, legumes, dried fruits|
|Chloride||primary anion, maintains pH balance, enzyme activation, gastric hydrochloric acid component||In infants: loss of appetite, failure to thrive, weakness, lethargy, hypokalemia, metabolic acidosis||table salt, seafood, milk, meat, eggs|
|Magnesium||bone component, nerve impulse transmission, protein synthesis, enzyme activation||depression, muscle weakness, tetany, abnormal behavior, convulsions, growth failure||nuts, legumes, cereal grains, soybeans, parsnips, chocolate, molasses, corn, peas, carrots, seafood, brown rice|
|Phosphorus||structural component of bone, teeth, cell membrane, phospholipid, nucleic acids, nucleotide coenzymes, ATP-ADPphosphate transfer, pH regulation||neuromuscular, skeletal, and renal problems, rickets, osteomalacia, anorexia||meat, poultry, fish, eggs, milk, milk products, nuts, legumes, cereal grains, chocolate|
|Potassium||water, electrolyte, and pH balances, cell membrane transfer||severe: hypokalemia1, muscular weakness, mental apathy, cardiac arrhythmias, paralysis, bone fragility, increased blood pressure, increased salt sensitivity, risk of kidney stones||avocado, banana, dried fruits, orange, peach, potatoes, dried beans, tomato, wheat bran, dairy products, eggs|
|Sodium||water, pH and electrolyte regulation, nerve transmission, muscle contraction||anorexia, nausea, muscle atrophy, poor growth, weight loss||table salt, meat, seafood, cheese, milk, bread, vegetables (most food except fruits)|
|Sulphur||detoxification mechanisms, component of sulfur containing amino acids, and structurally associated with thiamin, biotin and lipoic acid||unknown||meat, poultry, fish, eggs, milk, cheese, legumes, nuts (high protein foods)|
Recommended Macromineral Intakes or Adequate Intakes2
Calcium: AI's (milligrams/day)
|Birth to 6 months||210 mg||210 mg||n/a||n/a|
|7-12 months||270 mg||270 mg||n/a||n/a|
|1-3 years||500 mg||500 mg||n/a||n/a|
|4-8 years||800 mg||800 mg||n/a||n/a|
|9-13 years||1,300 mg||1,300 mg||n/a||n/a|
|14-18 years||1,300 mg||1,300 mg||1,300 mg||1,300 mg|
|19-50 years||1,000 mg||1,000 mg||1,000 mg||1,000 mg|
|50+ years||1,200 mg||1,200 mg||n/a||n/a|
Magnesium: DRI's (milligrams/day)
Phosphorus RDI's (milligrams/day)
Sodium AI's (grams/day)
Since most of the daily intake of chloride comes along with sodium in the form of sodium chloride the AI's for chloride are generally set to the same as for sodium on a molar basis. Adequate intake of sodium will result in adequate intake of chloride. For young adults on to 50 years this would mean about 3.8 grams of salt per day.3
The AI's for potassium are at about 4.7 grams (4700 mgs) a day for all adults. Most people would do well to consume more potassium and don't get near this amount. However, this does not mean that one should turn to potassium supplements. Although excess potassium is readily excreted by the kidneys a quick build up of potassium in the body through suppements that exceeds the kidneys capacity could have devastating and even deadly results.
There is no AI or DRI for sulfur due to the fact that a diet that includes enough protein is generally rich in sulfur. And sulfur is even found in the water we drink. Perhaps in the future this macromineral will be more extensively studied.
Sulfur is the third most abundant mineral based on percentage of total body weight. The sulfur-containing amino acids (SAAs) are methionine, cysteine, cystine, homocysteine, homocystine, and taurine. Sulfur-containing amino acids are more abundant in animal and cereal proteins than in legume proteins, with the ratio of methionine to cysteine tending to be higher in animal proteins than in plant sources.