Calcium and Bone
CALCIUM & BONE METABOLISM
Parathyroid glands are located in the neck on the rear tip surfaces of the thyroid gland. Parathyroid gland produces parathyroid hormone. Parathyroid hormone controls the calcium levels in the body
- Parathyroid hormone which increases blood calcium by
- Stimulating osteoclasts to break down bone
- Increase absorption of calcium in gut by activating Vitamin D
- Promote reabsorption of calcium by kidneys
- Deficiency occurs due to neck surgery, genetics and autoimmune disorders resulting in
- Symptoms include distal extremity numbness and tingling, carpopedal spasm, seizures, irritability, confusion, delirium, tetany, heart failure, wheezing, stridor, low blood pressure (hypotension)
- Excess production due to adenoma, familial/genetic or drug induced (lithium)
- Symptoms include: kidney stones, decreased bone mass (osteopenia), weakness, fatigue, psychosis, constipation, excessive urination (polyuria), excessive thirst (polydipsia), and nausea.
- Elevated Calcium (Hypercalcemia) can be due to
- Hyperparathyroidism, Cancer, Granulomatous disease (Tb, Sarcoid), hyperthyroidism, immobilization, medication
- Low Calcium levels (Hypocalcemia) can be due to
- Hypoparathyroidism and Vitamin D deficiency
Osteoporosis is a disease of the bones that leads to increased risk of fracture. In osteoporosis, bone mineral density is reduced.
- Risk factors include
- Advanced age, female sex, Caucasian background, family history, low body weight, excessive alcohol intake, insufficient intake of Calcium and Vitamin D, Early menopause (age<45), premature ovarian failure, medical/surgical menopause, steroid and medication use, rheumatological disorders, malabsorptive disorders
Osteomalacia in adults is a mineralization disorder in which structural integrity of the bond is reduced because of deficient supply of calcium to bone surface.
- Risk factors include
- Very low Calcium intake, calcium malabsorption (i.e. celiac disease), phosphorus deficiency, some types of cancer and lack of sunlight resulting in Vitamin D deficiency
Paget Disease of bone interferes with your body's normal recycling process, in which new bone tissue gradually replaces old bone tissue. Over time, the disease can cause affected bones to become fragile and mis-shapen. Paget's disease of bone most commonly occurs in the pelvis, skull, spine and legs.
- Symptoms include bone pain, fracture, paraplegia, deafness, shortness of breath (high output cardiac failure)