SAVED
File name .JPG
File alt. text
Image should be px wide x px tall.
Select Image
home - Nutrition - Vitamins - Vitamin A Excess and Deficiency Written by Dr Sebastian Zeki

Vitamin A Excess and Deficiency

Occurs with single doses of >660,000 units (>200 mg) Symptoms include nausea, vomiting, vertigo, and blurry vision. Toxic dose10 x RDA (10,000 micrograms of retinol or 33,000 IU) Toxicity of vitamin A increased byLiver and kidney diseaseAlcoholismSome drugs, such as tetracyclines. Vitamin A Excess Impairment of the phagocytes and T cells. Xerophthalmia - due to inadequate function of the lacrimal glands Clinical: Night blindness and Bitot's spots (areas of abnormal squamous cell proliferation and keratinization of the conjunctiva), progressing to corneal xerosis and keratomalacia. Repalcement of hair follicles with mucus-secreting glands. Poor bone growth ReplacementTo prevent clinical vitamin A deficiency, Vitamin A supplements can be distributed at 4 to 6 month intervals at the following doses:Infants < 6 months of age -Non breast-fed: 50,000 IU orally Breast fed: 50,000 IU orallyInfants 6 to 12 months of age: 100,000 IU orallyChildren >12 months of age: 200,000 IU orallyMothers: 200,000 IU orally, within 8 weeks of deliveryPregnant women only get10,000 IU daily or 25,000 IU weekly (teratogenicity at high doses) Vitamin A- Clinical manifestations of deficiency Acute toxicity Chronic toxicity SymptomsDry skin, Nausea,HeadacheFatigue, IrritabilityHepatomegaly with stellate cell proliferation (lead to cirrhosis)AlopeciaHyperostosis, osteoporosisIncreased cerebrospinal fluid pressure (pseudotumor cerebri)Teratogenic in first trimester. Vitamin A- Clinical manifestations of deficiency and Excess Written by Dr Sebastian Zeki

Related Stories

•Oral anticoagulant switching in patients with atrial fibrillation: a long-term cohort study using population-level administrative data

•Neuroprotective effects of cell-free supernatant from Pediococcus pentosaceus TAP041 against glycation- and inflammation-associated stress responses

•Secondary Metabolites from Diaporthe eres SK3, an Endophytic Fungus of Sellaginella kraussiana Sw. Collected from the Northeast Indian Hills, Exhibits Potential in Vitro Bioactivities

•Impact of Obesity, Sarcopenia, and Nutritional Status on Spine Surgery Patients

•Associations of dietary diversity with type 2 diabetes in two Chinese cohorts: a multi-omics study