Older Adults 2

Question 1

What are conditions faced by older adults related to nutrition status?

Answer 1

1. atrophic gastritis
2. osteoporosis
3. macular degeneration
4. cognitive decline
5. body composition changes
6. sarcopenia

Question 2

What is atrophic gastritis? What are the causes?

Answer 2

Atrohpy of the stomach mucosa
Causes:
1. Autoimmune atrophic gastritis (rare)
2. overuse of NSAIDS - advil, alleve, neproxin, ibuprofin, motrin, aspirin
3. excessive alcohol intake
4. #1 cause is immflamation due to infection with H. Pylori
5. aging

Question 3

How can atrophic gastritis affect physiology?

Answer 3

• atrophy of the lining of the stomach
• impairs function of parietal cells
• HCl & intrinsic factor are affected which can lead to vitamin B12 deficiency

Question 4

What are the functions of HCl?

Answer 4

• denatures protein, and seperates B12 from protein
• activates pepsinogen
• inhibits microbial growth (due to low pH)

Question 5

What are the functions of intrinsic factor?

Answer 5

• glycoprotein that acts as a carrier for the absorption of vitamin B12 in the ileum
  without it, B12 absorption is impaired

Question 6

What are the steps of B12 absorption? (exam 10 pt question)

Answer 6

1. B12 is consumed in diet, naturally found in animal protein (synthetic is not bound to protein)
2. Salivary Glands produce haptocorrin which enters the stomach with protein/B12
3. HCl & pepsin in stomach release dietary B12 that is bound to protein
4. Haptocorrin binds to B12
5. In the small intestine - trypsin cleaves B12 from haptocorrin
6. IF produced is released into the chyme and enters SI where it binds with the freed B12
7. B12/intrinsic factor enter enterocyte
8. IF degrades in enterocyte, Transcobalamin picks up B12 to deliver to liver and then other organs

Question 7

What are the 2 main functions of vitamin B12?

Answer 7

1. cofactor for methionine synthase - converts homocysteine (immflamatory molecule) to methionine; part of the folate cycle
2. cofactor for enzyme needed for hemoglobin synthesis (erythropoetin)

Question 8

What are the effects of atrophic gastritis?

Answer 8

• Low acids, lack of IF
• vitamin B12 deficiency (limb numbness and tingling, unsteady walking, mental changes)
• Magaloblastic anemia (weak, lightheaded, chest pain, palpitations, tinnitus)

Question 9

What are the causes of vitamin B12 deficiency? What are the effects?

Answer 9

• causes: atrophic gastritis, PPI’s, bariatric surgery, strict vegan diet
• effects: macrocytic/megaloblastic anemia
• may be alleviated with B12 supplementation

Question 10

What are the recommendations for Vitamin B12 supplementation?

Answer 10

• consume in animal or fortified products
• supplements recommended for vegans & older adults
• B12 shots might be needed for autoimmune or severe cases of deficiency