{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Lecture-38 - Vitamins A diverse group of organic compounds...

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Vitamins A diverse group of organic compounds that either cannot be synthesized at all by the body, or synthesized in sufficient amounts to maintain normal tissue function. Thirteen vitamins have been identified in humans. Vitamins are categorized as either water-soluble (vitamin C and the B vitamins) or fat-soluble (vitamins A, D, E and K).
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Laetrile (B17) Pangamic acid (B15) Orotic acid (B13) Gerovital (H3) bioflavinoids Some compounds normally synthesized by the body may be “ conditionally essential ” under conditions such as prematurity, genetic aberrations or parenteral feeding. These include choline and carnitine . There is no evidence that the following compounds are really vitamins: Two vitamins have precursor forms that are metabolized to the active form of the vitamin: vitamin A ( β -carotene) and niacin (tryptophan).
Image of page 2
Types of Vitamin Deficiencies 1. Primary – due to inadequate intake 2. Secondary – malabsorption, drug-nutrient interactions, increased vitamin needs due to stress or disease. Inadequate intake in western society it’s usually seen in (1) individuals undergoing drastic dieting; (2) the poor and destitute; (3) those whose lifestyles predispose them to vitamin deficiencies (eg., “bachelor’s scurvy”); (4) those restricting their diets for philosophical/religious reasons; and (5) weaning practices in some cultures. Drug-nutrient interactions – many therapeutic agents interfere in vitamin absorption ( neomycin affects B12 absorption). Excessive alcohol, caffeine and nicotine intake can interfere with vitamin metabolism.
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Increased vitamin needs During growth, pregnancy/lactation, and in postsurgical, burn and trauma patients as well as those with some diseases. In pregnant women, administration of folate above recommended daily intake levels reduces incidence of neural tube defects. Some vitamins (egs., A, E, C) may decrease risk of getting some cancers (anti-oxidant effects). Should I partake of megavitamin therapy? For water-soluble vitamins , you’ll excrete the excess vitamins taken in; tissue levels will not rise. Niacin (B3) and pyridoxine (B6) can produce some toxicity. Among the fat-soluble vitamins, vitamins A & D can produce toxicity.
Image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern