Vitamin D deficiency in a man with multiple myeloma

Vitamin D deficiency is extremely common in multiple myeloma, and it represents a surrogate for clinical multiple myeloma disease status. Patients may complain of dull, persistent, generalized musculoskeletal aches and pains with fatigue or decrease in muscle strength.

A 63 year old male with multiple myeloma on Bortezomib presented with worsening generalized musculoskeletal pain, weakness, and multiple falls. On initial examination he was pale with a depressed affect. He had resting tremor, generalized bony tenderness, worse on movement and weight bearing, muscle weakness, and a waddling gait. His bone studies showed features of osteomalacia with a very low Vitamin D level of less than 20 nmol/L. He was treated with 3000 units of Vitamin D daily and physiotherapy. After 4 months, although his multiple myeloma deteriorated, there was a significant decrease in his generalized musculoskeletal pain.

This case highlights that vitamin D deficiency is common in patients with multiple myeloma, and can cause generalized musculoskeletal pain and increase the risk of falls, yet it often goes unrecognized. In patients with non-specific musculoskeletal pain, and inadequate sun-exposure medical practitioners must have a high index of suspicion for vitamin D deficiency.