Week 12 , B12, Folate, Choline,

Question 1

Choline is a water-soluble nutrient typically found in foods rich in vitamin/s _______:

a. C
b. E
c. B’s
d. A

Answer 1

B

Choline is found in foods rich in B vitamins.

Question 2

True or false? Choline is an essential nutrient?

Answer 2

False.

Choline is synthesized in the body from other nutrients therefore is not considered essential.

Choline can be synthesized de novo from ethanolamine, when methionine or dimethylcysteine, or betaine is in adequate supply. The most abundant source of choline in the diet is lecithin.

However -https://www.hsph.harvard.edu/nutritionsource/choline/#:~:text=The%20Tolerable%20Upper%20Intake%20Level,to%20produce%20these%20side%20effects..

Question 3

The primary sign of choline deficiency is:

a. hyperalbumin
b. ketoacidosis
d. fatty liver
e. low kidney function

Answer 3

d. fatty liver

Question 4

Choline as a component of lecithin plays a key role in:

a. methyl group metabolism
b. carcinogenesis
c. lipid transport
d. all of the above

Answer 4

d. Choline is particularly noteworthy because it plays a key role in methyl group metabolism, carcinogenesis, and lipid transport as a component of lecithin.

(Lecithin consists of choline, inositol, linoleic acid, and phosphorus among others)

Question 5

The addition of choline to the diet _____ the need for activated methyl groups supplied by methionine.

a. increases
b. decreases

Answer 5

b. decreases.

Choline is generally added to diets to reduce the need for activated methyl groups supplied by methionine. It is more economical to add choline for these methyl groups than to add methionine.

Question 6

True or false? Choline levels in the body may decrease after exercise.

Answer 6

True.

Choline has been promoted to athletes to improve physical endurance by increasing fat lipolysis and acetylcholine production to increase muscle contractions and delay fatigue, although evidence does not support these claims ( Kraus, 442).

Question 7

Food sources rich in choline include:

a. eggs
b. fatty foods
c. peanuts
d. dairy
e. all of the above

Answer 7

e. all of the above

(also organ meat, caviar, fish, shiitake mushrooms, soybeans, beef, wheat germ, chicken/turkey, cruciferous vegges).

Question 8

The RDA for choline (men) is:

a. 550mg/day
b. 300mg/day
c. 100mg/day
d. 50mg/day

Answer 8

a. 550mg/day (and 425mg/day for women).

3,500mg/day is the TUL for men and women (likely due to over supplementation)

Question 9

True or false - choline supplements may cause GI side effects including breakdown to trimethylamine, which leads to a fishy body odor.

Answer 9

True. P.U.

*Fun fact - choline is neither a vitamin or mineral, however is often lumped with the B vitamins due to its similarities.

Question 10

Choline is absorbed in the:

a. jejunum
b. duodenum
c. ileum
d. all of the above

Answer 10

d. all of the above

Question 11

________ is a water soluble vitamin that occurs naturally in food. _________ is the synthetic form that is found in supplements and is added to fortified foods.

a. folate (B9), folic acid
b. folic acid, folate

Answer 11

a. folate is a water soluble vitamin that occurs naturally in food. Folic acid is the synthetic form that is found in supplements and is added to fortified foods.

Question 12

The following is true about folate:

a. Functions as an enzyme in single carbon transfers
b. Is involved in the maintenance of new cells
c. Is needed to make DNA and RNA
d. Is needed to make normal RBC’s and prevent anemia
e. all of the above

Answer 12

e. all of the above
* Folate is especially important during periods of rapid cell division and growth such as infancy, adolescence, and pregnancy.
* Folate is also essential for the conversion of homocysteine to methionine in the synthesis of s-adenosyl-methionine, and important methyl donor.

Question 13

The RDA for folic acid for a pregnant woman is:

a. 65mcg DFE* (Dietary folate equivalent)
b. 150mcg DFE
c. 400mcg DFE
d. 600mcg DFE

Answer 13

d. 600mcg DFE
* At least 85% of supplemental folic acid is estimated to be bioavailable when taken with food, whereas only about 50% of folate found in food is bioavailable. Based on this the Food and Nutrition Board (FNB) defines DFE as follows:

1 mcg = 1mcg food folate
1 mcg DFE = 0.6 mcg folic acid from fortified foods or dietary supplements consumed with foods.
1 mcg DFE = 0.5 mcg folic acid from dietary supplements taken on an empty stomach.

Question 14

Dietary sources of folate include:

a. avocado, spinach
b. broccoli, mustard greens
c. green peas, kidney beans
d. all of the above

Answer 14

d. all of the above

*a = 59/58 mcg (15%) DFE per serving
b = 52 mcg (13%)
c. 46/47 (12%)

Question 15

The tolerable upper limit for folic acid is:

a. 500mcg/day
b. 1000 mcg/day
c. 1500 mcg/day

Answer 15

b. 1000 mcg/day

* 400 mcg/ day is recommended for pregnancy

Question 16

True fact - The active form dietary folate or folic acid is converted to to be used by the body is 5, 10-methyltetrahydrofolate (5-MTHFA). A genetic mutation in the enzyme that metabolizes folate (methylenetetrahydrofolate) results in the inability to convert folate/folic acid to its usable form. The results it folate deficiency, unless it is consumes in the methylated form as methyltetrahydrofolic acid (MTHFA).

Answer 16

yes

Question 17

B12 deficiency affects \_\_\_% of people over 60.
A. 40%
B. 25-30%
C. 10-15%
D. 50%

Answer 17

C. 10-15%

Question 18

True/False:

Vitamin B12 is the only water-soluble vitamin to be stored in appreciable amounts in the body

Answer 18

True

Question 19

The TUL for B12 is...
A. 1500mcg
B. 2000mcg
C. 1g
D. None of the above

Answer 19

D. there is no TUL

Question 20

Fun Fact: In the blood, 80% of vitamin B12 is in the methylcobalamin form

Answer 20

20% is the adenosylcobalamin form

Question 21

B12 is 
A. found exclusively in plant foods
B. found exclusively in animal foods
C. found in both animal and plant foods
D. none of the above

Answer 21

Found exclusively in animal foods, however bacteria in some plants can contribute to b12 such as mushrooms

Question 22

\_\_\_\_\_\_\_\_ may increase vitamin B12 requirements and exacerbate neurological signs/symptoms of vitamin B12 deficiency
A. Vitamin C
B. Folate
C. Vitamin K
D. Niacin

Answer 22

B. Folate

Question 23

Adenosylcobalamin is the main storage form of vitamin B12 in the\_\_\_\_\_\_\_ and accounts for 50-70% of the stored vitamin B12 in the body. 
A. lungs
B. Kidney
C. Jejejum
D. Liver

Answer 23

D. Liver - The remainder of vitamin B12 in the body is stored in the bone, kidneys, heart, brain, spleen and blood.

Question 24

Serum b12- reflects both status and intake.

*body will pull from tissues to keep serum levels normal, tissue levels can be low while serum is normal- advised to check beyond just serum b12.

Answer 24

Plasmaholotranscobalamin- Indicates absorption

MMA can be used for B12 status as well

Question 25

\_\_\_\_\_\_\_ is a protein made in the stomach that is needed for B12 absorption. This protein also declines with age.
A. protease
B. glutamine
C. instrinsic factor
D. None of the above

Answer 25

C. intrinsic factor

Question 26

In those over \_\_\_\_\_ years of age, there is increased likelihood of food-bound malabsorption of vitamin B12, so supplementation is often recommended. 
A. 25
B. 35
C. 45
D. 50

Answer 26

D. 50

Question 27

Fun fact: When your body can’t make enough healthy red blood cells because it lacks vitamin B-12 - this is pernicious anemia

Answer 27

over 50% of patients with pernicious anemia go on to develop iron- deficient anemia