Vitamin A Deficiency Clinical Presentation

Updated: Oct 12, 2016
  • Author: George Ansstas, MD; Chief Editor: George T Griffing, MD  more...
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Presentation

History

Subclinical forms of VAD may not cause any symptoms, but the risk of developing respiratory and diarrheal infections is increased, the growth rate is decreased, and bone development is slowed. Patients may have a recent history of increased infections, infertility secondary to impaired spermatogenesis, or recent spontaneous abortion secondary to impaired embryonic development. The patient may also report increased fatigue, as a manifestation of VAD anemia.

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Physical

Signs and symptoms of vitamin A deficiency include the following:

  • Bitot spots - Areas of abnormal squamous cell proliferation and keratinization of the conjunctiva can be seen in young children with VAD.
  • Blindness due to retinal injury - Vitamin A has a major role in phototransduction. The cone cells are responsible for the absorption of light and for color vision in bright light. The rod cells detect motion and are responsible for night vision. In the rod cells of the retina, all-trans-retinol is converted into 11- cis -retinol, which then combines with a membrane-bound protein called opsin to yield rhodopsin. [20] A similar type of reaction occurs in the cone cells of the retina to produce iodopsin. The visual pigments absorb light at different wavelengths, according to the type of cone cell they occupy. VAD leads to a lack of visual pigments; this reduces the absorption of various wavelengths of light, resulting in blindness.
  • Poor adaptation to darkness (nyctalopia)
  • Dry skin
  • Dry hair
  • Pruritus
  • Broken fingernails
  • Keratomalacia
  • Xerophthalmia
  • Corneal perforation
  • Follicular hyperkeratosis (phrynoderma) secondary to blockage of hair follicles with plugs of keratin.
  • Other signs of VAD include excessive deposition of periosteal bone secondary to reduced osteoclastic activity, anemia, keratinization of mucous membranes, and impairment of the humoral and cell-mediated immune system.
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Causes

The risk of VAD is increased in patients suffering from fat malabsorption, cystic fibrosis, sprue, pancreatic insufficiency, IBD, or cholestasis, as well as in persons who have undergone small-bowel bypass surgery. The risk is also increased in vegans, refugees, recent immigrants, persons with alcoholism, and toddlers and preschool children living below the poverty line. These patients should be advised to consume vitamin A.

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