What laboratory test is most appropriate for a 72-year-old woman with severe dementia and osteoporosis with old pathologic vertebral fractures, taking calcium, donepezil, and occasional acetaminophen?

From the Research

The most appropriate level to obtain for this 72-year-old woman with severe dementia and osteoporosis is 25-hydroxyvitamin D (option A). This patient is at high risk for vitamin D deficiency due to her bedbound status, which limits sun exposure, and her history of osteoporosis with pathologic vertebral fractures. Vitamin D is essential for calcium absorption and bone health, and deficiency is common in elderly, institutionalized patients. Since she is already taking calcium supplements but continues to have osteoporosis, assessing her vitamin D status would help determine if supplementation is needed to optimize her bone health and prevent further fractures.

Key Considerations

• The patient's bedbound status and limited sun exposure increase her risk of vitamin D deficiency 1
• Vitamin D deficiency is common in elderly, institutionalized patients and can contribute to osteoporosis and increased risk of fractures 2
• Assessing vitamin D status can help determine if supplementation is needed to optimize bone health and prevent further fractures
• While calcium, parathyroid hormone, phosphate, and thyroid-stimulating hormone levels might provide useful information in some contexts, vitamin D assessment is most directly relevant to managing her existing osteoporosis in this clinical scenario

Relevant Evidence

• A study published in 2011 found that a 25-hydroxyvitamin D level of at least 35 ng/mL is required to reduce the risk of secondary hyperparathyroidism and bone loss 3
• Another study published in 2011 recommended a minimum desirable serum 25-hydroxyvitamin D level of 75 nmol/L (30 ng/mL) to sustain bone density, calcium absorption, and minimize risk of osteomalacia and rickets 1
• A 1996 study found that vitamin D supplementation can improve calcium absorption, suppress parathyroid hormone, and reduce the risk of fractures in elderly women with vertebral fractures 4
• A 2018 review discussed the potential benefits and harms of calcium supplementation in osteoporosis, highlighting the importance of considering vitamin D status in the management of osteoporosis 5
• A 1996 study found that vitamin D2 supplementation is ineffective in stimulating calcium absorption in elderly women with vertebral osteoporosis, while alfacalcidol may be more effective in managing vertebral osteoporosis 4
• A study published in 1996 found that correcting calcium and vitamin D insufficiencies in elderly people can prevent hip fractures and reduce the risk of osteoporosis 2