Calcium
This electrolyte abnormality can cause hypocalcemia that is resistant to treatment until it is corrected
What is hypomagnesemia
This hormone increases serum Ca by stimulating bone resorption, increasing renal Ca reabsorption, and activating vitamin D
What is PTH
This vitamin deficiency is the most common cause of hypocalcemia in outpatient practice
What is vitamin D
These cells act as the primary mechanosensors in bone, detecting mechanical stress and microdamage to trigger remodeling
What are osteocytes
This is the age the USPFTF age recommend osteoporosis screening begin in women
What is age 65 and above AND postmenopausal women <65 with risk factors
This fraction of total serum Ca is physiologically active ionized Ca
What is ~50% physiologically active, 40% protein bound (albumin mostly), 10% with anions
This disease is the most common cause of hypercalcemia characterized by elevated or inappropriately normal PTH
What is primary hyperparathyroidism or malignancy
This form of vitamin D is measured clinically to assess vitamin D status
What is 25-hydroxyvitamin D
This signaling system is the master regulator of osteoclast differentiation and bone resorption
What is RANK-RANKL-OPG system
- RANKL binds RANK on osteoclast precursors → osteoclast formation
- OPG acts as a decoy receptor that blocks RANKL
- the RANKL/OPG ratio determines osteoclast activity
This class of medications increases risk of osteoporosis with a specific dose/duration threshold that is incorporated into FRAX calculations
Glucocorticoids (e.g., prednisone ≥2.5 mg/day for >3 months)
This formula is used to adjust total calcium for hypo/hyper albumin levels on CMP
What is:
Corrected Ca (mg/dL) = Serum Ca (mg/dL) + 0.8 × (4.0 − Serum Albumin (g/dL))
(pulled from MD Calc)
This condition causes compensatory elevation of PTH due to chronic hypocalcemia, most commonly from CKD or vitamin D deficiency
What is secondary hyperparathyroidism
This condition commonly develops when vitamin D deficiency causes chronic hypocalcemia leading to compensatory elevation of PTH
What is secondary hyperparathyroidism
This form of vitamin D increases intestinal calcium absorption, renal calcium reabsorption, and bone resorption when needed
What is calcitriol
This eGFR is a general contraindication of bisphosphonates in patients with CKD
bisphosphonates are gen contraindicated when eGFR<35 due to risk of worsening renal function
This medication is commonly used for rapid but temporary lowering of calcium in severe hypercalcemia while waiting for bisphosphonates to work
What is calcitonin
This condition causes mild hypercalcemia with low urinary calcium excretion and is often mistaken for primary hyperparathyroidism?
What is familial hypocalciuric hypercalcemia (FHH)
This adult bone disease results from defective mineralization due to vitamin D deficiency
What is osteomalacia
This renal enzyme converts 25-hydroxyvitamin D into active calcitriol and is stimulated by PTH
What is 1-alpha hydroxylase
This tool calculates a patient's 10 year fracture risk
This is the triad of findings is found in milk alkali syndrome, one of the most common causes of hypercalcemia due to widespread calcium supplementation
What is hypercalcemia, metabolic alkalosis, and renal insufficiency
This syndrome causes severe, prolonged hypocalcemia after parathyroidectomy due to rapid skeletal uptake of calcium
What is hungry bone syndrome
This disease occurs when vitamin D deficiency causes failure of mineralization at the growth plate
What is rickets
This bone signaling pathway is essential for osteoblast differentiation and bone formation and is targeted by some anabolic osteoporosis therapies
What is Wnt–β-catenin signaling pathway
This type of fracture occurring from a fall from standing height or less is considered diagnostic of osteoporosis and an indication for treatment regardless of bone mineral density
What is a fragility fracture