Hypocalcaemia (low serum calcium found)

Fasting laboratory tests

• Serum calcium
• Serum albumin
• PTH (on the same sample as the serum calcium)
• PTH, reimbursed in France (hypocalcaemia after thyroidectomy, or dialysis patient)if neededAfter thyroidectomy (diagnosis and follow-up of hypoparathyroidism) or in dialysis patients, PTH falls within the NABM indications of procedure 0983: do not write “NR” (not reimbursable in France); in other situations, use the previous line (NR) ^[2].
• Serum magnesium
• Serum phosphate
• Serum creatinine with eGFR
• 25-hydroxyvitamin D (reimbursed in France)
• Alkaline phosphatase (if osteomalacia suspected)if needednon-French guidelineSuspected osteomalacia (long-standing vitamin D deficiency) ^[1].
• Serum lipase (if abdominal pain, pancreatitis suspected)if needednon-French guidelineAbdominal pain suggesting acute pancreatitis, a cause of hypocalcaemia ^[3].
• Creatine kinase (CK) (if rhabdomyolysis suspected)if needednon-French guidelineSuspected rhabdomyolysis, a cause of hypocalcaemia ^[3].
• Ionised calcium (if hypoalbuminaemia or acid-base disorder; not reimbursed in France, rarely feasible in the community)if neededIn case of doubt (hypoalbuminaemia, acidosis or alkalosis); sample without tourniquet, anaerobic, transported on ice; not reimbursed in primary care ^[2,4].

24-hour urine collection

• Urinary calciumif neededSymptomatic adult whose treatment must start quickly: urinary calcium and creatinine on a spot sample, measured without waiting for fasting; the 24-hour collection then helps adjust treatment but must not delay it ^[4].
• Urinary creatinine on a urine sampleif neededSymptomatic adult whose treatment must start quickly: urinary calcium and creatinine on a spot sample, measured without waiting for fasting; the 24-hour collection then helps adjust treatment but must not delay it ^[4].
• Urinary calciumif neededAdult without symptoms (or whose treatment can wait): 24-hour urine collection in the absence of treatment, urinary creatinine checking that the collection is complete ^[4].
• 24-hour urinary creatinineif neededAdult without symptoms (or whose treatment can wait): 24-hour urine collection in the absence of treatment, urinary creatinine checking that the collection is complete ^[4].

Fasting laboratory tests

• Serum calcium
• Serum albumin
• Serum magnesium
• PTH (on the same sample as the serum calcium)