1 / 23

Vitamin A deficiency

Vitamin A deficiency. Supervision Prof. Dr . Mervat Salah. Intended Learning Outcomes. By the end of this lecture, students will have a general overview on vitamin A in it’s deficiency health outcomes. BACKGROUND.

donoma
Download Presentation

Vitamin A deficiency

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Vitamin A deficiency Supervision Prof. Dr . MervatSalah

  2. Intended Learning Outcomes • By the end of this lecture, students will have a general overview on vitamin A in it’s deficiency health outcomes.

  3. BACKGROUND • Vitamins are organic substances that are essential for several enzymatic functions in human metabolism • Thiamine was discovered in 1912 & was thought to be a vital amine compound & thus the term vitamin was invented

  4. VITAMINS • Vitamins are classified according to solubility into fat soluble & water soluble. • 13 vitamins are known, 4 fat soluble (KEDA) & 9 water soluble (C, Folate & the B group).

  5. VITAMIN A • Vitamin A is a generic term for many related compounds. • Retinol (alcohol), Retinal (aldehyde) are often called preformed vitamin A. Retinal can be converted by the body to retinoic acid which is known to affect gene transcription. • Body can convert b-carotene to retinol, thus called provitamin A.

  6. FUNCTIONS • Vision:integrity of eye & formation of rodopsin necessary for dark adaptation. • Regulation of gene expression: vital to cell differentiation & physiologic processes • Immunity: important for activation of T lymphocyte, maturation of WBC & integrity of physiological barrier. • Growth & development

  7. Nutrient Interactions • Zinc deficiency interfere with vitamin A metabolism in several ways: • It decreases the synthesis of retinol binding protein, which transports retinol to tissues. • It decreases the activity of the enzyme retinyl palmitate, which is necessary for release of retinol from the liver. • Zn is needed for the enzyme that convert retinol into retinal.

  8. Nutrient Interactions/2 • Iron & vitamin A. • Vitamin A deficiency may exacerbate IDF • Vitamin A supplementation improves iron status among children & pregnant women. • Combining vitamin A with iron controls IDA more quickly & effectively than using iron alone.

  9. VITAMIN A UNITS • 1 mg of retinol = 6 mg of b-carotene. • 3 mg of retinol = 10 international units of vitamin A. • 100 mg carrots contain 10 mg of b-carotene.

  10. Recommended Allowance

  11. RICH DIETARY SOURCES

  12. Vitamin A deficiency • Deficiency of vitamin A leads to: • Night blindness & xerophthalmia • Growth retardation • Acquired immune deficiency • Keritinization of epithelia in RT, GIT & UT with increased risk of RTI, malabsorption & UTI.

  13. THERAPEUTIC USES • Vitamin A deficiency • Boosting immunity of infants • Skin disorders • Acute promyelotic leukemia • Cancer prevention (lung & breast)

  14. TOXICITY • Vitamin A in excess leads to: • Dermatitis with xanthosis cutis • Hepatosplenomegaly • Bone pain & increased risk of fracture • Pseudotumor Cerebri

  15. Xeropthalmia in rat - dryness of the corneaEarly stages are curable

  16. Cured with 6 days treatment with Vitamin A

  17. Vitamin A deficiency Night Blindness

  18. Follicular hyperkeratosis. Goose flesh. Pustulation occurs and is confused with acne.

  19. Histological section of skin. Hair follicle with hyperkeratosis. (Excess keratinized tissue).

  20. Recommended text book • Manual dietetic book

More Related