Military Strategies for Sustainment of Nutrition and Immune Function in the Field (1999) / Chapter Skim
Currently Skimming:
12 Vitamin A and Immune Function
12 Vitamin A and Immune Function
Pages 279-288
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 279... ...
, it is now well established that widespread immune alterations, anemia, and increased infectious disease morbidity and mortality occur during vitamin A deficiency. The use of vitamin A supplements to enhance immunity has been demonstrated in the recent series 1 Richard D
|
From page 280... ...
Other conditions besides vitamin A deficiency can cause night blindness, including advanced glaucoma, papillary abnormalities involving a small pupil, retinitis pigmentosa, and certain rare retinal disorders involving rod function of the retina. Mild vitamin A deficiency is also characterized by keratinizing, squamous metaplasia of the conjunctive.
|
From page 281... ...
Several factors may contribute to the development of vitamin A deficiency, including inadequate intake of vitamin A-containing foods, malabsorption due to infections in the gut, liver disease, the acute phase response and abnormal urinary losses of vitamin A, zinc deficiency, concomitant protein energy malnutrition, and increased utilization of vitamin A during infections. Diarrheal disease and intestinal parasites may interfere with the absorption of vitamin A
|
From page 282... ...
Pregnancy and lactation represent a period of high risk in women for the development of vitamin A deficiency. Night blindness is not uncommon among pregnant women in developing countries, and a recent case control study from Nepal suggests that pregnant women with night blindness have increased infectious disease morbidity (Christian et al., 1996~.
|
From page 283... ...
Pathologic changes in the conjunctive associated with night blindness include keratinizing metaplasia of the conjunctive and loss of goblet cells and mucus (Natadisastra et al., 1987~. In the respiratory tract, vitamin A deficiency is associated with loss of ciliated respiratory epithelium, goblet cells, and mucus (Goldblatt and Benischek 1927; Wolbach and Howe, 1925~.
|
From page 284... ...
Children with clinical or subclinical vitamin A deficiency have depressed IgG responses to tetanus toxoid compared with children supplemented with vitamin A (Semba et al., 1992~. There are few data regarding antibody responses in vitamin A-deficient adults, probably because deficiency is generally uncommon, except in those with chronic infections such as HIV infection.
|
From page 285... ...
/d in healthy adults may increase the risk of vitamin A toxicity or of birth defects in women of childbearing age. AUTHOR'S CONCLUSIONS Vitamin A deficiency is a nutritionally acquired immunodeficiency disorder that primarily affects infants, preschool children, pregnant women, and lactating women.
|
From page 286... ...
1995. Vitamin A inadequacy in socioeconomically disadvantaged pregnant Iowan women as assessed by the modified relative dose response (MRDR)
|
From page 287... ...
1993. The effects of retinol on in vitro immunoglobulin synthesis by cord blood and adult peripheral blood mononuclear cells.
|
From page 288... ...
It would be very interesting to see. We are doing a study in adults with conjugated pneumococcal vaccine in Baltimore using vitamin A and zinc in a factorial design to see whether that will increase their immune responses.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.