Minerals in Bottled Water

Written by Michael Mascha
Monday, 12 September 2005 15:00
Compared with wine, differences in taste among waters are quite subtle. But they are nevertheless discernible. Local geological strata impart water with different minerals, giving every single-source water a unique set of characteristics. This section describes the most common minerals found in bottled water as well as the benefits these minerals can provide.
MAGNESIUM (Mg++)Almost all human cells contain some level of magnesium, and adults need three to four hundred milligrams of magnesium every day. Magnesium is important for the regulation of muscle contractions and the transmission of nerve impulses, and it activates energyproducing enzymes. Bone structure also relies on magnesium, and the element expands blood vessels, which lessens the risk of heart attack. Nervousness, lack of concentration, dizziness, and headaches or migraines may result from magnesium deficiency. Most bottled waters have below 20 mg/l of magnesium, though Donat Mg is an extremely high example with 1,000 mg/l.
CALCIUM (Ca++)Adults need about eight hundred milligrams of calcium per day; babies don’t require as much, but fifteen- to nineteen-year-olds need significantly more. The many benefits of calcium include stabilizing bone structure, teeth, and cell membranes; ensuring nerve and muscle impulses are properly transmitted; and helping prevent blood clots. Bones decalcify (osteoporosis) and fractures become more likely if a body is not getting enough calcium. Bottled water usually has less than 100 mg/l of calcium, but a few examples (such as Contrex and Sanfaustino) have about 500 mg/l.
POTASSIUM (K+)Two to four grams are usually a sufficient day’s supply of potassium. Children and young people should pay particular attention to their intake, since potassium aids the growth of cells. The pressure of water between cells is regulated by potassium, which also makes sure each cell gets enough food. Potassium has special roles to play in muscle contraction and heartbeat. Potassium deficiency can weaken skeletal muscles and make smooth muscles tired. Typical potassium content in bottled water is less than 5 mg/l, but some (such as Ferrarelle and Malavella) can have as much as 50 mg/l.
SODIUM (Na+)A person’s level of exertion largely determines his or her daily requirement of sodium. Normally about three grams are necessary, but severe physical stress can bring the requirement up to fifteen grams or more. The heart’s metabolism is affected by sodium, as is the regular contraction of the heart. Today, we rarely have to worry about sodium deficiency: Salt is an integral part of many foods, especially those that are highly processed. Sodium ranges from 10 mg/l in most bottled waters to 1,200 mg/l in a few, such as Vichy Catalan and Vichy Célestins.
SULFATES (SO4)Sulfates are the salts of sulfur. They help the liver detoxify the body and aid digestion by stimulating the gall bladder. Sulfates in high doses act as a laxative. Fish, meat, and milk contain sulfates, which are an important component of protein. The human body absorbs only small amounts of sulfates, but these amounts are sufficient to stimulate peristalsis by binding magnesium and sodium to water in the intestine. This effect makes mineral waters rich in sulfates, which taste slightly bitter, suitable as “nonalcoholic bitters” after a meal. Most bottled waters have well below 100 mg/l of sulfates, but San Pellegrino and a few others can reach 500 mg/l.
BICARBONATE (HCO3)Present in all biological fluids, bicarbonate is essential for maintaining our bodies’ pH balance. The substance is also found in stomach secretions. Lactic acid generated by physical activity is neutralized by bicarbonate dissolved in water; a similar process raises the pH of some acidic foods. The typical range for bicarbonate in bottled water is 50 to 200 mg/l, but it can reach up to about 1,800 mg/l in waters such as Apollinaris, Gerolsteiner, and Borsec.
SILICA (SiO2)Most adults need between twenty and thirty milligrams of silica daily. Silica reduces the risk of heart disease and may prevent osteoporosis; it also helps repair tissue by serving as an antioxidant. Hair and nails are strengthened by silica. If bottled waters contain any silica, it’s usually less than 20mg/l; the higher levels in waters such as Fiji and Antipodes are well below 100 mg/l.
TRACE ELEMENTS The human body needs iron, iodine, copper, fluoride, zinc, and other trace elements as well as minerals. The recommended daily intake is fractions of a milligram for some substances and a few milligrams for others.