What is the diagnosis code for severe vitamin D deficiency?

ICD-10 Diagnosis Code for Severe Vitamin D Deficiency

The ICD-10 diagnosis code for severe vitamin D deficiency is E55.9 (Vitamin D deficiency, unspecified), or more specifically E55.0 (Rickets, active) if rickets is present, or M83.9 (Adult osteomalacia, unspecified) if osteomalacia has developed.

Understanding Severe Vitamin D Deficiency

Severe vitamin D deficiency is clinically defined as serum 25-hydroxyvitamin D [25(OH)D] levels below 10-12 ng/mL (25-30 nmol/L), which dramatically increases the risk for osteomalacia and nutritional rickets. 1

• This threshold represents the level at which classic vitamin D deficiency diseases manifest with visible skeletal changes and metabolic bone disease 1
• Levels below 20 ng/mL (50 nmol/L) are considered deficient, while 20-30 ng/mL represents insufficiency 2, 3, 4
• Severe deficiency below 12 ng/mL increases risk of excess mortality, infections, and many other diseases 4

Clinical Coding Considerations

Primary ICD-10 Codes

• E55.9 is the most commonly used code for vitamin D deficiency when no specific manifestation is documented 5
• E55.0 should be used when active rickets is present in children 1, 2
• M83.9 is appropriate when adult osteomalacia has developed as a consequence of severe deficiency 1

Supporting Documentation Requirements

• Document the actual 25(OH)D level in ng/mL or nmol/L to justify the "severe" designation 1, 5
• Note any clinical manifestations such as symmetric low back pain, proximal muscle weakness, muscle aches, or throbbing bone pain over sternum or tibia 3
• Record any secondary hyperparathyroidism, which develops progressively as levels fall below 20 ng/mL and worsens with severe deficiency 5, 6

Important Clinical Context

When Inflammation Complicates Diagnosis

• Plasma vitamin D levels are significantly reduced when C-reactive protein (CRP) exceeds 40 mg/L, complicating interpretation 1
• Nearly all vitamin D values fall below reference ranges in the presence of significant inflammation, regardless of true nutritional status 1
• Consider timing of sample collection and influence of acute illness when documenting deficiency 1

Risk Factors to Document

• Severe kidney or liver dysfunction increases deficiency risk 1
• Bed-ridden and chronically ill patients are at high risk 1
• Malabsorption syndromes (post-bariatric surgery, inflammatory bowel disease, celiac disease) require documentation 5
• Dark skin pigmentation is associated with 2-9 times higher prevalence of low vitamin D levels 5
• Obesity causes vitamin D sequestration in adipose tissue 5, 6

Common Coding Pitfalls to Avoid

• Do not use codes for active vitamin D analogs (calcitriol) deficiency - these are different conditions requiring different ICD-10 codes 5
• Avoid coding as "unspecified" when specific manifestations like rickets or osteomalacia are present - use the more specific codes E55.0 or M83.9 1
• Do not confuse vitamin D deficiency with secondary hyperparathyroidism - while related, hyperparathyroidism requires its own code (E21.1) in addition to the vitamin D deficiency code 5
• Document whether deficiency is nutritional versus due to malabsorption - this affects treatment approach and may require additional diagnosis codes 5

Treatment Implications for Coding

• Severe deficiency typically requires loading doses of 50,000 IU weekly for 8-12 weeks, which should be documented in the treatment plan 5, 3
• Follow-up 25(OH)D levels after 3-6 months are necessary to confirm adequate response and may affect ongoing coding 1, 5
• Target level of at least 30 ng/mL for anti-fracture efficacy should be documented as treatment goal 5