Orthopaedic Nurses Certification Board (ONCB) Metabolic/Inflammatory/Tumors Practice Exam

In a patient with osteomalacia, low serum calcium and elevated alkaline phosphatase levels are expected laboratory findings. Osteomalacia is characterized by the softening of bones, primarily due to a deficiency in vitamin D, which affects calcium absorption and mineralization of bone.

When the body does not adequately absorb calcium, the serum calcium levels drop, leading to hypocalcemia. In response to this low calcium level, the parathyroid hormone is released, which attempts to maintain calcium homeostasis, but this process can lead to bone demineralization and a subsequent increase in alkaline phosphatase. Alkaline phosphatase is an enzyme that increases when there is increased bone turnover or inadequate mineralization, such as in osteomalacia.

The other options do not accurately reflect the biochemical changes seen in osteomalacia. Therefore, the identification of low serum calcium alongside elevated alkaline phosphatase as characteristic findings assists in diagnosing this condition effectively.