What are the implications of hypocalcemia, normal renal function, and normal liver function in this patient?

From the Guidelines

The patient's lab results show mostly normal values, but the slightly low calcium level at 8.3 mg/dL warrants consideration for calcium supplementation, especially if the patient has symptoms of hypocalcemia or risk factors for bone disease, as suggested by the most recent guidelines 1. The kidney function appears normal with an eGFR of 105 mL/min/1.73m2, and electrolytes (sodium, potassium, chloride) are all within normal ranges. Liver function tests are generally normal with appropriate albumin, total protein, and bilirubin levels. The glucose level of 90 mg/dL is within the normal range, indicating normal blood sugar control. Some key points to consider in the management of this patient's condition include:

• Regular investigations including measurements of pH-corrected ionized calcium, magnesium, parathyroid hormone, and creatinine concentrations are recommended 1.
• Daily vitamin D supplementation is recommended for all adults, sometimes with calcium supplementation 1.
• Management using hormonally active vitamin D metabolites, eg, calcitriol, is reserved for more severe/refractory cases usually with endocrinologist consultation 1.
• Thyroid function should be assessed annually, as thyroid disease is common in adults with 22q11.2 deletion syndrome 1. Overall, this is a reassuring lab panel with no major abnormalities requiring immediate action, but close monitoring and consideration of calcium supplementation are necessary to prevent potential complications.

From the Research

Laboratory Results

The provided laboratory results show the following values:

• Sodium: 138 mmol/L (within the reference range of 136-145 mmol/L)
• Potassium: 4.1 mmol/L (within the reference range of 3.6-5.1 mmol/L)
• Chloride: 105 mmol/L (within the reference range of 98-107 mmol/L)
• CO2: 23 mmol/L (within the reference range of 22-32 mmol/L)
• Anion Gap: 10 (within the reference range of 6-18)
• Glucose: 90 mg/dL (within the reference range of 70-99 mg/dL)
• BUN: 11 mg/dL (within the reference range of 8-20 mg/dL)
• Creatinine: 0.73 mg/dL (within the reference range of 0.60-1.30 mg/dL)
• eGFR: 105 mL/min/1.73m2 (above the reference value of >=60 mL/min/1.73m2)
• BUN/Creatinine Ratio: 15.1 (within the reference range of 12.0-20.0)
• Calcium: 8.3 mg/dL (below the reference range of 8.9-10.3 mg/dL)
• AST (SGOT): 10 unit/L (within the reference range of 15-41 unit/L)
• ALT (SGPT): 13 unit/L (within the reference range of 7-52 unit/L)
• Alkaline Phosphatase: 37 unit/L (within the reference range of 32-91 unit/L)
• Total Protein: 6.4 g/dL (within the reference range of 6.1-7.9 g/dL)
• Albumin: 3.8 g/dL (within the reference range of 3.5-4.8 g/dL)
• Total Bilirubin: 0.4 mg/dL (within the reference range of 0.3-1.2 mg/dL)

Calcium and Vitamin D Supplementation

The low calcium level (8.3 mg/dL) may be addressed through calcium and vitamin D supplementation. Studies have shown that:

• Calcium citrate combined with vitamin D is effective in reducing the incidence of non-vertebral and hip fractures 2
• Calcium absorption is enhanced by vitamin D, with a significant increase in urinary calcium excretion when calcium is administered with vitamin D 3, 4, 5
• The combination of calcium and vitamin D supplements may have a positive effect on bone metabolism, particularly in postmenopausal women with osteopenia 6
• However, high intake of vitamin D may result in frequent hypercalciuria and hypercalcaemia, and may be associated with kidney stones 3

Key Findings

• Calcium and vitamin D supplementation may be beneficial for individuals with low calcium levels
• The combination of calcium and vitamin D supplements can enhance calcium absorption and have a positive effect on bone metabolism
• However, high intake of vitamin D should be approached with caution due to the potential risk of hypercalciuria and hypercalcaemia.