Calcium and Vit D and exam prep… Miriam Salib

Aims and Objective… Help you pass the exam??

Why do we need Calcium? Osteogenesis via Osteoblasts Blasts Build Bones, Clasts Cause Cavities AP – cardiac and Skeletal Muscle Ach exocytosis

What’s Normal?? 2.2 – 2.6 mmol/L 40% ionised and physiologically relavent 60% bound – mainly to albumin CORRECTION depending on how much albumin you have… Figures based on having 40g/L of Albumin But what if you have a patient that had 30g/L albumin? And what if your patient had 50g/L albumin?

Calcium regulation… The two most important hormones parathyroid hormone (PTH) and 1,25(OH) 2 D (the active form of vitamin D).

PTH –ve feedback loop… PTH secretion is stimulated by hypocalcemia, and it works through three mechanisms to increase Ca ++ levels: PTH stimulates the release of Ca ++ from bone, stimulating bone resorption. PTH decreases urinary loss of Ca ++ by stimulating Ca ++ reabsorption. PTH indirectly stimulates Ca ++ absorption in the small intestine by stimulating synthesis of 1,25(OH) 2 D in the kidney.

Hypocalcaemia – think “c” S & S Confusions and irritability Convulsions an fatigue Chovosteck’s sign Cataract Cardiac problems (ECG and Failure) Cramps spasms and tetany Chorea

Why? Causes What decreases? HypoParathyroidism PseudoHypoparathyroidism Idopathic Hypoparathyroidism DiGeorge Syndrome What Increases? Serum Phosphate Calcitonin Bisphosphonates – inhibits OC and moves Calcium from blood to bone Other - Pancreatitis

Ix and Tx Ix – after establishing that they have low calcium… PTH Vit D U+Es Mg Tx Acute – Calcium Gluconate infusion Chronic – Oral Calcium or calcitriol and treat underlying cause

Hypercalcaemia Hyperparathyroidism Adenoma 75% of causes there is one ademona 3F:1M !!! RENAL FAILURE! OESTITIS FIBROSA CYSTICA – bones turn soft and become deformed.

Ix and Tx Ix CT/USS/MRI/ Radioisotope sestamibi to locate Treat if There are complications Calcium is over 3mmol/L SYMPTOMSUNDERLYING CAUSE MEDICALDEHYDRATION BISPHOSPH… SURGICAL- EXCISE SINGLE ADENOMA - REMOVE ALL FOUR GLANDS AND REPLACE WITH….?

Other causes of Hypercalcaemia MALGINANCY Inc PTHrP release Release OC activating factors VIT D EXCESS FAMILIAL HYPOCALCIURIC HYPERCALCAEMIA E- TTALS

BONE, STONE, MOANS AND GROANS Bone and muscles – bone pain, lathargy and muscle weakness Renal stones, renal failure, polyuria => polydipsia, constipation, vomiting, Abdo Pain Psychosis, confusion, depression, presonality chnages

Ix and Tx Ix – after establishing that they have high calcium… PTH Vit D U + Es ESR, Bone Scan, FBCs Urine analysis TFTs, CXR Tx Rehydrate – normal saline and Stop Diuretics!! Bisphosphonate ?? Calcitonin

Vitamin D

Deficiency

Ix and Tx Ix - after establishing that they have low Vit D PTH U + Es Xray Bone Biopsy Tx Sunlight Oral Supplements (D2 and D3 and Calcium) I.M. Cholecaliferol every 6-12 months Calcitriol if there is renal disease