I am curious if people have anything to add to these brief excerpts (via quick web search) on calcium. The critical neuro-muscular connection is complex but interesting, as I believe I have neglected this important dietary component. Can any of you pharma members comment? Many thanks.
http://www.medicinenet.com/muscle_cramps/page2.htm
Low Blood Calcium, Magnesium. Low blood levels of either calcium or magnesium directly increase the excitability of both the nerve endings and the muscles they stimulate. This may be a predisposing factor for the spontaneous "true" cramps experienced by many older adults, as well as for those that are commonly noted during pregnancy
http://www.naturalways.com/calciumResearch.htm
There are two types of calcium. One type of calcium is tightly bound within the bone and the other more accessible type of calcium is found on the bone. The skeleton serves as a bank of minerals for the body. The body can borrow from the skeletal stores when blood calcium levels drop and return calcium to bones as needed.
A constant supply of calcium is necessary throughout our lifetime, but is especially important during phases of growth, pregnancy, and lactation (breast feeding). About 10-40% of dietary calcium is absorbed in the small intestine with the help of vitamin D (Somer, 1995; Mahan et al, 1996). The level of calcium absorption from dietary sources drops to 7 in post-menopausal women (Sourer, 1995). The body will absorb more calcium if there is a deficiency. Factors that improve calcium absorption include adequate amounts of protein, magnesium, phosphorous, and vitamin D. Conditions that reduce calcium absorption include high or excessive intakes of oxalates and phytates, found in foods such as spinach and unleavened whole wheat products. Consumption of alcohol, coffee, sugar, or medications such as diuretics, tetracycline, aluminum containing antacids, or stress can reduce absorption of calcium. Lack of exercise can reduce calcium absorption as well as cause an increase in calcium losses. These life habits can immobility lead to calcium deficiency. Calcium deficiency can increase risk of bone disorders such as osteoporosis.
Calcium Functions
(Sourer, 1995; Whitney et al, 1996; Sizer et al, 1997)
� Calcium is responsible for construction, formation and maintenance of bone and teeth. This function helps reduce the occurrence of osteoporosis.
� Calcium is a vital component in blood clotting systems and also helps in wound healing.
� Calcium helps to control blood pressure, nerve transmission, and release of neurotransmitters.
� Calcium is an essential component in the production of enzymes and hormones that regulate digestion, energy, and fat metabolism.
� Calcium helps to transport ions (electrically charged particles) across the membrane.
� Calcium is essential for muscle contraction.
� Calcium assists in maintaining all cells and connective tissues in the body.
� Calcium may be helpful to reduce the incidence of premature heart disease, especially if adequate intakes of magnesium are also maintained.
� Calcium may help to prevent periodontal disease (gum disease).
Calcium Deficiency
(Sourer, 1995, McCarron et al, 1987; McCarron et al, 1991)
� Calcium Deficiency in conjunction with high sodium intake is related to a higher risk of hypertension.
� Calcium Deficiency can lead to loss of calcium from the bone (initially from the jaw and the backbone), which can lead to deformity.
� Calcium Deficiency can cause extreme nerve sensitivity, muscle spasms, and leg cramps (called tetany) at very low levels in the blood.
http://dictionary.reference.com/
cal�ci�um
n. Symbol Ca
A silvery, moderately hard metallic element that constitutes approximately 3 percent of the earth's crust and is a basic component of most animals and plants. It occurs naturally in limestone, gypsum, and fluorite, and its compounds are used to make plaster, quicklime, Portland cement, and metallurgic and electronic materials. A