II. Epidemiology

  1. Vitamin D Deficiency is common in U.S.
  2. Incidence increasing due to Sunscreen use and less Time Outdoors
  3. Age over 65 are associated worldwide with Vitamin D Deficiency in >50% of people

III. Risk Factors: Infants

  1. Anticonvulsants
  2. Chronic disease with fat malabsorption
  3. Exclusively Breast-fed infant without Vitamin D supplementation
  4. Low maternal Vitamin D levels
  5. Lack of Sun Exposure
    1. Direct sunlight avoidance is recommended by AAP for those under 6 months
    2. Darker skin pigmentation (requires 3-6 fold more Sun Exposure)

IV. Risk Factors: Adults

  1. Age over 65 years
    1. Related to housebound status and decreased Vitamin D absorption
  2. Comorbid illness
  3. Malnourished
  4. Lack of Sun Exposure (or thorough sun screen use)
    1. Those with darker skin require 3-6 fold more exposure
  5. Renal disease (Renal Failure, Nephrotic Syndrome)
  6. Hepatic disease (Cirrhosis)
  7. Gastrointestinal malabsorption
    1. Gastric surgery (resection or Gastric Bypass)
    2. Crohn's Disease
    3. Cystic Fibrosis
  8. Small Bowel Resection
  9. Medications
    1. Anticonvulsant use (e.g. Phenobarbital, Phenytoin)
      1. Requires 2-5 fold more Vitamin D intake daily
    2. Corticosteroids (long-term use)
    3. Rifampin
  10. Total Parenteral Nutrition

V. Pathophysiology

  1. Effects of Vitamin D Deficiency
    1. Altered secretion of Parathyroid Hormone
    2. Altered mineral ion metabolism
      1. Hypocalcemia
      2. Hypophosphatemia
    3. Mineralization defects in skeleton
      1. Osteomalacia in adults
      2. Rickets in children
  2. Step-by-step outcome of Vitamin D Deficiency
    1. Malabsorption of calcium and phosphorus
      1. Calcium absorption drops to 10% of normal
      2. Phosphorus absorption drops to 60% of normal
    2. Inadequate intestinal calcium absorption
      1. Results in Hypocalcemia
      2. Severe Hypocalcemia occurs in later deficiency
    3. PTH secreted to compensate for Hypocalcemia
      1. Results in secondary Hyperparathyroidism
      2. Osteoclasts dissolve bone to mobilize calcium from bone
        1. Exacerbates Osteomalacia and Osteoporosis
    4. Increased PTH results in phosphate wasting
      1. Severe hypophophatemia results

VI. Symptoms

  1. Early
    1. Myalgias
    2. Proximal Muscle Weakness
      1. Associated with increased fall risk
  2. Later
    1. Bone pain
      1. Low Back Pain (especially older women)
      2. Extremity pain
    2. Secondary Hyperparathyroidism
      1. Osteoporosis
      2. Osteomalacia
    3. Symptomatic mineral disturbance
      1. See Hypocalcemia
      2. See Hypophosphatemia

VII. Signs

  1. Bone pain reproduced with pressure applied to Sternum or tibia

VIII. Differential diagnosis

IX. Associated Conditions: Conditions linked to Vitamin D Deficiency

  1. Osteomalacia and Osteoporosis
  2. Rickets
  3. Fall Risk
  4. Cardiovascular Disease
  5. Colon Cancer
  6. Depression

X. Labs

  1. Serum 25-Hyroxyvitamin D Level
    1. Preferred test (but expensive)
    2. Levels <20 ng/ml suggest deficiency
    3. Levels 20-30 ng/ml suggest insufficiency
  2. Ionized Serum Calcium
  3. Serum Phosphorus

XI. Management

  1. Treat Hypocalcemia
    1. Symptomatic Hypocalcemia or Ionized Calcium <3.2 mg/dl
  2. Treat Hypophosphatemia
  3. Vitamin D Replacement
    1. See Vitamin D Replacement
  4. Vitamin D maintenance
    1. Maintain Vitamin D between 30-40 ng/ml and 100 ng/ml
    2. See Vitamin D for maintainance doses

XII. Prevention

  1. Adequate dosing depends on latitude
    1. In northern climates 2000 IU daily may be more appropriate
    2. Higher doses may be required in those with risk factors above

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Ontology: Vitamin D Deficiency (C0042870)

Definition (CSP) condition due to a deficiency of vitamin D.
Definition (MSH) A nutritional condition produced by a deficiency of VITAMIN D in the diet, insufficient production of vitamin D in the skin, inadequate absorption of vitamin D from the diet, or abnormal conversion of vitamin D to its bioactive metabolites. It is manifested clinically as RICKETS in children and OSTEOMALACIA in adults. (From Cecil Textbook of Medicine, 19th ed, p1406)
Concepts Disease or Syndrome (T047)
MSH D014808
ICD9 268.9, 268
ICD10 E55 , E55.9
SnomedCT 190649007, 154728003, 190639009, 124886009, 34713006
English Deficiencies, Vitamin D, Deficiency, Vitamin D, Vitamin D Deficiencies, Unspecified vitamin D deficiency, VITAMIN D DEFICIENCY, Avitaminosis D NOS, Vitamin D deficiency, unspecified, DEFIC VITAMIN D, VITAMIN D DEFIC, vitamin D deficiency, vitamin D deficiency (diagnosis), avitaminosis D, avitaminosis D (diagnosis), Vitamin D deficiency NOS, Vitamin D Deficiency [Disease/Finding], d deficiencies vitamin, deficiency vitamin d, vitamin d deficiencies, d deficiencies vitamins, d deficiency vitamin, vitamin d deficiency, d deficiency vitamins, d vitamin deficiency, Avitaminosis D NOS (disorder), Deficiency of vitamin D (disorder), Hypovitaminosis D, Vitamin D Deficiency, Vitamin D deficiency, Avitaminosis D, Vitamin D deficiency (disorder), deficiency; vitamin, D, vitamin; deficiency, D, Avitaminosis D, NOS, Vitamin D deficiency, NOS
German VITAMIN-D-MANGEL, unspezifischer Vitamin D-Mangel, Vitamin-D-Mangel, nicht naeher bezeichnet, Vitamin D-Mangel, Vitamin-D-Mangel
Dutch niet-gespecificeerde vitamine-D-deficiëntie, deficiëntie; vitamine, D, vitamine; deficiëntie, D, Vitamine D-deficiëntie, niet gespecificeerd, vitamine-D-deficiëntie, Vitamine D-deficiëntie, Vitamine-D-gebrek, Deficiëntie, vitamine-D-, Vitamine-D-deficiëntie
French Carence en vitamines D non précisée, CARENCE EN VITAMINE D, Déficit en vitamine D, Carence en vitamine D, Carence en vit D
Italian Carenza non specificata di vitamina D, Carenza di vitamina D
Portuguese Carência de vitamina D NE, CARENCIA EM VITAMINA D, Carência de vitamina D, Deficiência de Vitamina D
Spanish Déficit no especificado de vitamina D, VITAMINA D, DEFICIT, déficit de vitamina D (trastorno), avitaminosis D, SAI, avitaminosis D, SAI (trastorno), avitaminosis D, deficiencia de vitamina D, hipovitaminosis D (trastorno), hipovitaminosis D, Déficit de vitamina D, Deficiencia de Vitamina D
Japanese ビタミンD欠乏、詳細不明, ビタミンD欠乏, ビタミンDケツボウショウサイフメイ, ビタミンDケツボウ, ビタミンD欠乏症
Swedish Vitamin D-brist
Finnish D-vitamiinin puutos
Russian VITAMINA D NEDOSTATOCHNOST', ВИТАМИНА D НЕДОСТАТОЧНОСТЬ
Czech Blíže neurčený deficit vitaminu D, Deficit vitaminu D, vitamin D - nedostatek, nedostatek vitaminu D
Korean 상세불명의 비타민 D 결핍증, 비타민 D 결핍증
Croatian Not Translated[Vitamin D Deficiency]
Polish Hipowitaminoza D, Niedobór witaminy D
Hungarian Nem meghatározott D-vitamin hiány, D-vitamin hiány
Norwegian D-vitaminmangel, Vitamin D-mangel