Calcium is essential for bones and teeth, heart, nerves, muscles, and blood clotting.

Calcium is the most abundant mineral element in your body, because it is the major element in bones. Serum and red blood cell calcium, however, do not represent bone mineral content or dietary adequacy.

Although most of the body’s calcium is stored in bones, some circulates in the blood. About 40% of the calcium in blood is attached to proteins in blood, mainly albumin. Protein-bound calcium acts as a reserve source of calcium for the cells but has no active function in the body.

Food sources of calcium:

Dark green vegetables, whole grains, nuts

Functions:

Calcium’s actions are as wide ranging as neuronal excitation, neurotransmitter release, innate immunity, hormonal secretion, and tone of smooth muscle cells in the vasculature, airways, uterus, gastrointestinal (GI) tract, and urinary bladder.

Optimum calcium status can help prevent lead toxicity.

Erythrocyte calcium as a marker:

Erythrocyte (whole blood) calcium is a useful marker in the management of people with hypertension and arrhythmias, renal failure, and even pre-menstrual syndrome.

Calcium accumulation in hair:

Calcium accumulation in hair can reflect the end result of the process of chronic mobilization from bone.

High levels in hair:

High levels are associated with calcium loss, which may indicate early signs of osteoporosis, especially in females in the age range of 30-50 yrs. High hair calcium in younger women may, by inference, indicate calcium loss that has not yet shown as bone density decrease.

Low levels in hair:

Low hair calcium may indicate increased risk of myocardial infarction with increased associated aortic calcium concentrations. However, low hair calcium in children reflects calcium distribution and is not directly related to dietary intake of calcium. Low hair calcium accompanied by other low element levels such as chromium, cobalt, magnesium, and manganese may suggest malabsorption. Hair treatments such as permanent solutions, bleach, or dyes may contain calcium and cause high hair calcium levels.

Urinary levels:

High levels:

Kidney stone formers are characterized by high urinary calcium, and potassium appears to decrease stone formation by decreasing urinary calcium levels. Conversely, low potassium intake results in higher calcium urinary levels. Other tests that may be helpful when calcium is abnormal are: bone density analysis, vitamin D, Deoxypyridinoline (deoxyPYD), and parathyroid hormone.