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

Vitamin A

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

•A case of rapidly growing conjunctival squamous cell carcinoma in a 3-year-old child with xeroderma pigmentosum: a case report

•Immuno-nutritional therapy in experimental autoimmune encephalomyelitis: a translational pathway to multiple sclerosis management

•Co-occurrence of acute hemolytic anemia and methemoglobinemia in a 74-year-old female with G6PD deficiency: A case report

•A case report of combined methylmalonic acidemia and homocysteinemia presented with cerebral sinus thrombosis and fluctuating cognitive impairment

•Computed tomography radiomics prediction of survival in hepatocellular carcinoma and is associated with ADH1A expression of the retinol metabolism pathway