Vitamin D deficiency in Adult
Vitamin D deficiency results from either lack of exposure to sunlight or impaired absorption. Malabsorption of vitamin D can occur in individuals with small bowel resections, celiac disease, inflammatory bowel disease, cystic fibrosis, or protein-losing enteropathies. Some medications (eg, phenytoin) can impair vitamin D absorption as well. Exclusively breastfed infants are also at high risk for vitamin D deficiency without adequate supplementation, as may also be seen in patients of any age with severe dietary restrictions. Elderly, institutionalized, chronically ill, and darkly pigmented individuals are at high risk for vitamin D deficiency as well.
Patients with vitamin D deficiency are often asymptomatic, but children may present with bowing of the legs, a preference to sit, and rickets, while adults may present with chronic muscle aches and pains. In severe cases, adults may present with osteomalacia, a condition of defective bone mineralization.
E55.9 – Vitamin D deficiency, unspecified
34713006 – Vitamin D deficiency
- Impaired absorption – celiac disease, gastric bypass, inflammatory bowel disease (eg, Crohn disease, ulcerative colitis), cystic fibrosis, phenytoin use
- Inadequate intake / exposure – exclusively breastfed infants, northern altitude, darkly pigmented skin
- Obesity – increased adipose tissue decreases the bioavailability of fat-soluble vitamin D
- Osteopenia / osteoporosis – decreased bone mass with typically normal calcium and phosphate levels; of note, phenytoin can also cause osteopenia
- Primary hyperparathyroidism – presents with osteitis fibrosa cystica, usually associated with hypercalcemia
- Secondary hyperparathyroidism – usually due to chronic renal disease, associated with hypocalcemia and hyperphosphatemia
- Multiple myeloma – bone pain with hypercalcemia
- Child abuse – must distinguish history and radiologic findings of rickets from child abuse
- Elder abuse – must distinguish history and radiologic findings of new fractures from osteomalacia and osteoporosis, especially in the setting of preexisting osteoporosis