The 7 Major Minerals in detail

Calcium

Calcium: The most abundant mineral in the body, with 99% found in bones and teeth, where it provides an essential structural component for their formation. Bones provide a reservoir of calcium that can be tapped to supply calcium to body fluids when its concentration in blood decreases. The other 1% is located in the body cells and fluids, where it is necessary for many essential functions such as blood clotting, hormone secretion, muscle contraction, and nerve transmission. Because so many critical body functions depend on calcium, its concentration in blood is tightly regulated so that it remains nearly constant regardless of dietary calcium intake. When calcium in blood falls even slightly, it will be released from bone to maintain steady blood calcium levels. The mechanism by which the body maintains calcium levels in the blood is known as calcium homeostasis. When blood calcium levels fall, the parathyroid gland releases parathyroid hormone (PTH), which stimulates the production of the active form of vitamin D (calcitriol) and thereby increases calcium absorption from the intestine. PTH and activated vitamin D work together to mobilize calcium from the bone and decrease calcium excretion from the kidneys. Functions: blood clotting, hormone secretion, muscle contraction, and nerve transmission. Calcium plays an indispensable role in bone and tooth formation. Bone is constantly being broken down and rebuilt in a process known as remodeling. Bone remodeling is necessary not only to maintain blood calcium levels, but it is also required during bone growth in the young, to allow bone to adapt to strain, and to repair the microscopic damage that occurs daily. Food Sources: Calcium-rich foods include milk, yogurt, and cheese, as well as some legumes, and certain dark-green leafy vegetables, such as Chinese cabbage, kale, and broccoli. Because these vegetables are low in oxalates the bioavailability of calcium is high: about 50% is absorbed. In contrast, though spinach is high in calcium, it is also high in oxalates that bind calcium and inhibit its absorption. Consequently, the bioavailability of calcium in spinach is low: only about 5% is absorbed. Calcium is also added to some grains, juices, tofu, and cereals. Milk, an excellent natural source of calcium, is usually also fortified with vitamin D, which works with calcium to promote bone health. Most studies indicate that calcium from food is better absorbed than calcium from supplements. This is likely due to improved absorption with meals and the tendency of people to consume smaller amounts of calcium more frequently, which likely improves absorption efficiency. Milk and many other dairy products are an important source of calcium. Sardines eaten with the bones are also a very good source. Bok Choy and broccoli are low in oxalates, so the calcium in these foods has a high bioavailability and is efficiently absorbed. *Parmesan cheese (hard): 503mg *Plain yogurt = skim milk: 338mg *Sardines (canned, w/edible bones): 325mg *Cheddar cheese: 303mg *Nonfat milk: 299mg *Black-eyed peas (boiled): 211mg *Mustard Greens (cooked): 165mg *Tofu (hard, calcium set): 163mg *Bok Choy = Chinese cabbage (chopped): 158mg *Almonds (dry roasted): 152mg *Spinach (boiled): 122mg *Amaranth (cooked): 116mg *Broccoli (chopped, cooked): 62mg *Whole wheat bread (1 slice): 52mg Recommendations: The Institute of Medicine has set the AI for calcium at 1,000 milligrams per day for men and women aged 19 to 50 years Deficiency: Osteopenia, Osteoporosis Toxicity/UL: Tolerable Upper Intake Level (UL) is set at 2,500 milligrams. Although it is tempting to think that supplements are a "sure thing" to confirm that you are getting enough calcium, supplementation can potentially push intake to higher-than-recommended levels, especially when added to daily food sources that are fortified with calcium. Studies show that more than 60% of women older than 60 years take calcium supplements, which could push their intake close to the UL. High dietary intakes may cause constipation and can interfere with iron absorption. Although rare in healthy people, excess intake may contribute to hypercalcemia, or excess calcium in the blood. Contrary to what is commonly believed, there is little evidence that high calcium intake promotes the formation of kidney stones.

Chloride

Chloride: Sodium and chloride are primarily found outside cells and potassium is typically found inside cells. Functions: The minerals sodium, potassium, and chloride maintain fluid balance in the body, transmit nerve impulses, and help muscles contract. When dissolved in bodily fluids, such as blood and urine and the fluids inside and outside our cells, these electrically charged minerals are known as electrolytes. In addition to its role in fluid balance, chloride also forms half of hydrochloric acid (HCl), found in the stomach's gastric juices. Food Sources: Recommendations: Deficiency: Because sodium is abundant in the American diet, chloride deficiencies are extremely rare. Toxicity/UL: Overconsumption of chloride, like sodium, increases blood pressure.

Magnesium

Magnesium: An adult body contains about 25 grams of magnesium, most of it—about 50% to 60%—is found in the bones; the rest is in the cells and fluids of the body. Functions: Magnesium (Mg) is a cofactor in more than 300 chemical reactions in the body. Magnesium plays a role in the transport of ions across the cell membrane, a process that is important to muscle contraction, nerve impulse conduction, and maintaining the rhythm of the heart. Magnesium is involved in extracting energy from carbohydrates, fats, and protein, as well as using that energy to perform work; and it plays a role in protein production. Magnesium is also necessary to convert vitamin D into its active form (calcitriol) to increase calcium absorption and thus plays an important role in bone health. Food Sources: Magnesium is present in all food groups in small quantities. Nuts, whole grains, and leafy greens are good sources. *Quinoa: 118mg *Brown Rice: 86mg *Almonds (roasted): 79mg *Spinach (boiled): 78mg *Swiss chard: 75mg *Cashews (roasted): 74mg *Pollock (baked): 73mg *Dark chocolate 70%: 65mg *Oatmeal: 63mg *Black beans (cooked): 60mg *Peanut butter: 49mg *Acorn squash (baked): 44mg *Avocado (raw, pureed): 33mg *Banana (1med raw): 32mg *Nonfat milk: 27mg *Chicken breast (roasted): 20mg *Broccoli (cooked): 12mg Recommendations: RDA Men 19-50: 400-420mg RDA Women 19-50: 310-320mg Deficiency: Approximately 60% of American adults do not consume the recommended intake level of magnesium, but outright deficiency symptoms are rare, because the kidneys limit excretion when intake is low and the body may absorb more. However, low intakes of magnesium are a risk factor for osteoporosis. Marginal or moderate magnesium deficiencies may also increase the risk of atherosclerosis, cancer, diabetes, and hypertension. There is ongoing research about the role of magnesium in preventing and managing these disorders. Toxicity/UL: Excess consumption from the diet is also rare, but toxicity can occur from supplement misuse.

Phosphorus

Phosphorus: Phosphorus (P) is the second most abundant mineral in the body and is present in every cell of the body. Functions: plays a critical role in bone health and is an essential component of bone and cartilage, phospholipids, DNA, and RNA. It is also involved in energy metabolism, and a multitude of enzymes and other proteins depend upon phosphorus to regulate their activity. Phosphorus is important in the maintenance of proper acid-base balance in the body. Food Sources: found in most protein-rich foods, such as meats and dairy, and because many food additives also contain phosphorus Recommendations: Deficiency: Phosphorus deficiency is rare, in part because the mineral is found in most protein-rich foods Toxicity/UL: there is some concern that Americans may be chronically overconsuming phosphorus, a potential problem considering that increased blood levels of the mineral have been associated with cardiovascular and other types of chronic diseases, particularly in people with kidney disease.

Potassium

Potassium: Potassium (K), the primary electrolyte within cells only 3% of American adults have usual intakes of potassium that exceed the Adequate Intake (AI) levels set by the Institute of Medicine. Indeed, so many of us do not get enough of the mineral that in 2010, the Dietary Guidelines for Americans identified potassium as a "nutrient of public concern." Sodium and chloride are primarily found outside cells and potassium is typically found inside cells. Functions: The minerals sodium, potassium, and chloride maintain fluid balance in the body, transmit nerve impulses, and help muscles contract. When dissolved in bodily fluids, such as blood and urine and the fluids inside and outside our cells, these electrically charged minerals are known as electrolytes. works together with sodium (and chloride) to maintain fluid balance. Potassium also functions as a co-factor for certain enzymes, helps nerves transmit and muscles contract, plays a role in nutrient transport, and helps to maintain the electrical activity of the heart to sustain a steady heartbeat. Food Sources: Found in a wide range of minimally processed foods, particularly fruits and vegetables. Veggies contain the highest amounts of potassium per kcal. *Dried apricots: 1,101mg *Baked potato (1 med): 941mg *Tomato juice (low sodium): 556mg *Orange juice: 496mg *Lima Beans (cooked): 484mg *Swiss chard (boiled): 480mg *Nonfat milk: 448mg *Pork loin (broiled): 439mg *Banana (1 med): 422mg *Yogurt (plain, low-fat): 398mg *Atlantic Salmon (cooked): 326mg *Black Beans (cooked): 306mg *Pistachios (dry-roasted) = Nectarine: 285mg *Broccoli (chopped, cooked): 229mg *Chicken breast (broiled): 220mg *Cantaloupe: 208mg *Carrots (raw, chopped): 205mg *Brown rice (cooked): 154mg *Watermelon: 85mg *Whole wheat bread (1 slice): 81mg Recommendations: A diet that emphasizes foods rich in potassium (the DASH diet, for example) may help mitigate some of the effects of excess sodium by increasing sodium excretion in the urine. Potassium may also help relax blood vessel walls, which can also lower blood pressure. Deficiency: Potassium deficiency, when serious—such as when there is excessive fluid loss through vomiting, diarrhea, use of diuretics, or kidney disorders—can lead to hypokalemia, a disorder characterized by fatigue, muscle weakness, abnormal heart rhythms, increased calcium excretion, and reduced insulin production. Milder forms of potassium deficiency—which are common in the United States, as most Americans only get about half the potassium they should—can increase the risk of hypertension, stroke, heart attacks, and other health problems. Toxicity/UL: Toxicity associated with excess consumption of potassium is extremely rare and would likely only result from dietary supplement misuse. However despite the prevalence of low intake, multivitamin mineral supplements in the United States contain only about 2% of the AI for potassium because of the risk of side effects, in particular low heart rate and abnormal heart rhythm. Potassium supplementation may sometimes be warranted, but should be prescribed and monitored by a health care provider because of potential side effects.

Sodium

Sodium: Sodium and chloride are primarily found outside cells and potassium is typically found inside cells. Sodium (Na) is a mineral we are all familiar with, in part because it is widely consumed as table salt, which is otherwise known as sodium chloride (NaCl). Sodium is used extensively in food processing and is often added to foods during cooking and at mealtimes to improve taste. The sodium content of packaged foods is a mandatory component of the Nutrition Facts Panel on food labels. Functions: The minerals sodium, potassium, and chloride maintain fluid balance in the body, transmit nerve impulses, and help muscles contract. When dissolved in bodily fluids, such as blood and urine and the fluids inside and outside our cells, these electrically charged minerals are known as electrolytes. An essential nutrient, sodium is the primary electrolyte responsible for maintaining fluid balance between cells and throughout the body. It plays a crucial role in regulating blood pressure, and is the major positively charged ion in extracellular fluids such as blood. It is also required to transmit nerve impulses and contract muscles, and is involved in the active transport of a number of nutrients. For instance, sodium is required to move glucose and amino acids into cells. Its role in the active transport of a variety of compounds also means that it is indirectly needed to maintain the body's acid-base balance and a stable pH. Food Sources: Currently, average U.S. sodium consumption is about 3,400 milligrams a day, but that number varies by age and sex. We get most of our sodium from processed and restaurant foods, with only about 10% coming from salt added at the table and another 10% coming from "fresh" unprocessed foods. *Processed and Restaurant foods: 77% *Naturally occurring: 12% *Added while eating: 6% *Home cooking: 5% Recommendations: The Institute of Medicine has set the AI level for sodium at 1,500 milligrams per day for men and women aged 19 to 50 years, noting that needs can be increased in endurance athletes who perspire a lot and people who work in hot and humid conditions. When purchasing processed foods, select 'reduced sodium' or 'low sodium' varieties and watch the serving sizes. *even if a food doesn't taste salty, sodium may be present in large quantities. Check the Nutrition Facts Panel for accurate information. *If you eat more than one serving of a food, your sodium intake will increase. *The Nutrition Facts Panel lists the Percent Daily Value %DV of sodium in one serving of food. *The %DV for sodium is based on 100% of the recommended amount of sodium, which is less than 2,400 milligrams (MG) per day *5%DV (120 mg) or less of sodium per serving is low *20%DV (480 mg) or more of sodium per serving is high *The American Heart Association has designated 6 commonly eaten foods that are loaded with sodium as the 'salty 6.' These include: bread, cold cuts, pizza, poultry, soup, and sandwiches. Deficiency: Toxicity/UL: The US ingests 50% more than the government-recommended amounts—one in every three Americans has hypertension. Overconsumption of sodium is common and increases the risk of hypertension, defined as having a blood pressure of at least 140/90 mmHg most of the time. On average, blood pressure rises progressively with intakes of sodium above 2,300 milligrams per day. Hypertension is a major risk factor for cardiovascular disease and stroke. The UL for adults 19 years and older is 2,300 milligrams daily. The Dietary Guidelines for Americans recommend limiting sodium intake to 2,300 milligrams per day but advise all adults 51 years and older, all African Americans older than two years, and all individuals with diabetes, high blood pressure, or chronic kidney disease, to consume no more than 1,500 milligrams per day. (This high-risk group comprises more than half of the U.S. population.) Although reducing sodium intake to this level has been demonstrated to reduce the risk of hypertension in these at-risk groups, there is currently no evidence that it actually reduces the risk of heart disease and stroke. In fact, there is some evidence that low sodium intake (less than 2,300 mg) may actually be associated with adverse health effects in some subgroups.

Sulfer

Sulfur: Sulfur (S) is a mineral that occurs in our diet as a component of other compounds. It is present in the vitamins thiamin and biotin; and it is present in two of the amino acids (cysteine and methionine) that are found in our body's proteins, as well as those that we eat. When we need to synthesize sulfur-containing compounds, the ultimate source of that sulfur is almost invariantly one of those amino acids. Functions: Food Sources: sulfur is a component of all proteins Recommendations: Deficiency: Because sulfur is a component of all proteins, deficiency is virtually unknown. Toxicity/UL: Toxicity is also rare because the body can excrete excess sulfur in the urine.