Vitamin A Deficiency

Aka: Vitamin A Deficiency, Bitot Spot

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II. Pathophysiology

  1. See Vitamin A
  2. Vitamin A Deficiency disrupts Corneal cell differentiation
    1. Results in Corneal Epithelium disruption and Dry Eye (Conjunctival Xerosis)
    2. Results in hyperkeratinization of ocular epithelium
  3. Vitamin A is also the source of derived Retinol
    1. Retinol deficiency results in rhodopsin deficiency, key to Retinal rods
    2. Rods are key to low light Vision and peripheral Vision
  4. Vitamin A Deficiency also affects skin
    1. Causes overall skin dryness and skin hyperkeratosis
  5. Other Vitamin A Deficiency effects
    1. Gastrointestinal System and respiratory system may also be affected
    2. Immune dysfunction may occur
      1. Vitamin A is a Cofactor for regulatory T Cells

III. Causes

  1. Diets lacking Vitamin A (see Vitamin A for sources)
    1. Restrictive eating patterns (e.g. Autism)
  2. Alcoholism
  3. Liver Disease
  4. Fat malabsorption (or bile flow disorder)
    1. Vitamin A is a fat soluble Vitamin
    2. Cystic Fibrosis
    3. Celiac Disease
    4. Inflammatory Bowel Disease
    5. Bariatric Surgery

IV. Signs

  1. Decreased Visual Acuity
    1. Night Blindness
    2. Retinal deterioration
    3. Blindness (leading cause of preventable childhood blindness worldwide)
  2. Disrupted Corneal Epithelium
    1. Dry bulbar Conjunctiva (Xerophthalmia)
      1. See Dry Eye
    2. Bitot Spots
      1. Small foamy white or gray Plaques under Conjunctiva
    3. Corneal Ulceration and scarring
    4. Endophthalmitis
  3. Skin changes
    1. Skin Hyperkeratosis (Phrynoderma, milia)
    2. Skin dryness

V. Labs

  1. Serum Retinol <20 mcg/dl

VI. Differential Diagnosis

  1. See Keratitis
  2. See Corneal Clouding
  3. See Dry Eye

VII. Management

  1. Precautions
    1. Narrow spectrum between therapeutic doses and liver toxicity
      1. Avoid excessive intake of Vitamin A
    2. Early management of Vitamin A Deficiency decreases the risk of longterm eye complications
      1. Dry Eye (Xerophthlamia) responds well to Vitamin A replacement
      2. Irreversible eye changes (e.g. Corneal scarring) occurs with delayed treatment (>1 month to 1 year)
  2. Replacement protocol 1 for Vitamin A Deficiency AND Xerophthalmia
    1. Age-Based Dose
      1. Age <6 months: 50,000 IU/dose
      2. Age 6-12 months: 100,000 IU/dose
      3. Age >12 months: 200,000 IU/dose
    2. Timing
      1. Dose 1: Give at time of diagnosis (day 1)
      2. Dose 2: Give next day after diagnosis (day 2)
      3. Dose 3: Give 2 weeks after diagnosis (day 14)

VIII. Prevention

  1. Prophylactic dosing in children at high risk for Vitamin A Deficiency (developing regions, WHO)
    1. Age 6 to 11 months: 100,000 IU for 1 dose
    2. Age 1 to 5 years: 200,000 IU every 4 to 6 months
  2. Other populations in which Vitamin A supplementation may be needed
    1. High risk women in pregnancy (developing world)
    2. Bariatric Surgery patients

IX. Resources

  1. Vitamin A Deficiency (StatPearls)
    1. https://www.ncbi.nlm.nih.gov/books/NBK567744/

X. References

  1. Andiescu (2026) Crit Dec Emerg Med 40(1): 15-7
  2. Jhun et al. in Herbert (2016) EM:Rap 16(9): 8-10

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