Vitamin D deficiency in Adult
Alerts and Notices
SynopsisVitamin D deficiency refers to a condition characterized by low serum levels of vitamin D. Vitamin D is a fat-soluble vitamin that is responsible for calcium homeostasis and bone health. Vitamin D increases the efficiency of calcium and phosphorus absorption from the small intestine and aids in the maturation of osteoclasts in the bone.
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
Differential Diagnosis & PitfallsLaboratory evidence of low vitamin D serum levels is critical to making a diagnosis of vitamin D deficiency. However, the patient's history can help elucidate the underlying cause of the diagnosis. It is also important to keep in mind other conditions affecting the bones if a patient presents with serious physical findings.
- 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
Drug Reaction DataBelow is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.
Vitamin D deficiency in Adult