Rare Case of Severe Hypocalcemia Due to PTH Resistance Related to Diet Pill

Introduction: The production of parathyroid hormone (PTH) is essential for calcium the maintenance of normal mineral metabolism. Parathyroid cells have cell-surface calciumsensing receptors, even small changes in extracellular Ca induce rapid changes in PTH secretion. Hypocalcaemia is a well-recognized manifestation of magnesium deficiency. We present rare case of severe hypocalcemia due to PTH resistance caused by hypomagnesemia related to diet pill. Case Report: 61 year old Hispanic obese female with chronic gastritis on omeprazole 20 mg daily, no other significant past medical and surgical history, not taking any prescribed medications presents to ED with complaints of tingling and numbness around the mouth, abdominal cramps, chest pain, shortness of breath and anxiety. On arrival calcium was found to be 6.0mg/dl(8.2–10.2mg/dl) with ionized calcium of 0.60mmol/l(1.13-1.32mmol/l) and EGFR>90ml/min, Albumin-4.0g/l, Magnesium-1.1mg/dl(1.6–2.3mg/dl), Phosphorus-6.1mg/dl(2.4–4.5mg/dl),rest of the electrolytes were normal. Patient was given IV calcium gluconate 2g and magnesium which helped improving her symptoms. PTH was 1700pg/ml(23-73pg/ml), low Vitamin D 25-hydroxy 20ng/dl(30-100ng/dl). Urinary calcium was <1mg/dl(2.0–17.5mg/dl). Vitamin D1,25- dihydroxy 34pg/ml(18-78pg/ml), PTH-like peptide levels 0.6pmol/l(<4.2pmol/l). EKG was normal no QT interval changes. For 4 weekspatient was taking weight loss medication was given to her by her brother called nucific-bio-x4. Patient had lost 4 pounds while taking the medication and had suppression of appetite. Physical features of pseudohypoparathyroidism were not seen. Patient had poor dietary intake of calcium, denied taking vitamin D supplements. Patient was given calcium acetate 2001 mg TID with meals, calcitriol 0.5mcg daily and calcium gluconate 2g IV intermittently was given. That improved her calcium levels to 6.8mg/dl with ionized calcium-0.90mmol/l. Magnesium was replaced IV and discharged on magnesium oxide 400mg BID to maintain magnesium the normal range. The patient was given loading dose of ergocalciferol 50,000 IUfor 8 weeks. At the time of discharge repeat PTH levels were 1600 pg/ml and calcium levels were 8.2mg/dl. 3D CT of the neck did not parathyroid mass. After discharge patient continued on oral calcium and magnesium to maintain calcium levels between 8.4–10.2mg/dl. After discharge calcium levels were 8.6mg/dl, vitamin D 25-hydroxy levels were 32ng/dl and maintenance dose of vitamin D3 2000 IU daily also continued. Nucific-bio-x4 pill was discontinued. Conclusion: In conclusion, severe life threatening hypocalcemia can occur with unsupervised weight lossmedications due to malabsorption of magnesium in patient with likely mutation in magnesium receptors causing PTH resistance. Vitamin D deficiency worsens hypocalcemia resulting into secondary hyperparathyroidism.