Lecture 6: Nutritional Supplements

Question 1

Functions of iron

Answer 1

1) Transport oxygen in blood via heme groups (e.g. hemoglobin + myoglobin)
2) Energy metabolism
3) Immune system

Question 2

Iron requirements in males

Answer 2

• 14-18 years old: RDA = 11 mg/day

- Adult: RDA = 8 mg/day

Question 3

Iron requirements in females

Answer 3

• 14-18 years old: RDA = 15 mg/day

- Adult: RDA = 18 mg/day

Question 4

Why might females need more iron?

Answer 4

Menstrual loss

Question 5

Best source of iron?

Answer 5

Organ meats + clams

Question 6

Best source for iron bioavaliability?

Answer 6

Meats + fish (heme iron)

Question 7

Why are non-heme forms of iron absorbed badly?

Answer 7

Plant-based products have other compounds that bind up iron

• Oxalates (fruits, veggies)
• Phytates (whole grains)

Question 8

Enhance iron absorption

Answer 8

1) Eat with vit C
2) Eat with meat
3) Use iron cooking utensils

Question 9

Reasons for iron deficiency (6)

Answer 9

1) Poor diet
2) Menstrual loss
3) Exercise induced hemolysis -> hematuria
4) Gastrointestinal losses
5) Inflammation
6) Small amounts in sweat

Question 10

Types of iron deficiencies

Answer 10

1) Anemia
2) Iron deficiency w/o anemia
3) Sports anemia

Question 11

__% of people on earth has anemia

Answer 11

25-30%

Question 12

Anemia diagnosis: cut-off levels for hemoglobin

Answer 12

Men:

Question 13

Difference between anemia & iron deficiency w/o anemia

Answer 13

Anemia = hemoglobin levels low

iron deficiency = serum ferritin levels low

Question 14

Serum ferritin is an indicator of…

Answer 14

Fe storage in the body

Question 15

Is iron deficiency w/o anemia detrimental to athletes? Which type?

Answer 15

Yes, endurance (high reliance on oxygen)

Question 16

Define: sports anemia

Answer 16

Hemoglobin concentration is low because of high blood volume

Question 17

Who should take Fe supplements?

Answer 17

Diagnosed anemic (blood work test)

Question 18

Fe supplements come in the form of…

Answer 18

ferrous salts (gluconate, sulfate, fumarate)

Question 19

Who is at risk for iron deficiency?

Answer 19

1) Female (athletes)
2) Vegetarians
3) History of anemia/iron deficiency

Question 20

Hemochromatosis

Answer 20

Genetic condition; iron is accumulated in the liver instead of absorbed

Question 21

AI for Ca intake

Answer 21

• 50 y.o. = 1200 mg/day

- At risk athletes = 1500 mg/day + 800 IU vit D

Question 22

What affects Ca absorption?

Answer 22

• Vit D helps (milk)
• Oxalates hinder (vegetables)
• Caffeine, sodium, alcohol hinders

Question 23

Ca supplementation may increase risk of…

Answer 23

heart attack

Question 24

Why might Ca supplementation be risky?

Answer 24

Narrow range for optimal intake

• Adult = 1000 - 2500 mg/day
• > 50 y.o. = 1200 - 2000 mg/day

Question 25

Benefits of milk (4)

Answer 25

1) Vit D 2) Calcium 3) Riboflavin (vit B) 4) 9 g best quality protein

Question 26

How can vit D do so much?

Answer 26

modulate the expression of >1000 genes

Question 27

Best effect of vit D + study finding

Answer 27

- Bone health | - High dose (>800 IU/day) prevents hip + non-vertebral fracture in people >65 y.o.

Question 28

DRI for vit D

Answer 28

- 600 IU - [Canadian osteoporosis] Low risk adults = 400-1000 IU - [^] >50 y.o. or med risk = 800-1000 IU

Question 29

Which organization will have the highest dietary vit D intake recommendation? Why?

Answer 29

Canadian Cancer Society | - vit D from diet > sun (skin cancer)

Question 30

Ways to get vit D

Answer 30

- Fortified milk products - Fatty fish - Sunlight (way better source than any food)

Question 31

Naked 10-20 min in summer sun = how much vit D produced?

Answer 31

As much as 10 000 IU

Question 32

Sunlight is insufficient for vit D production where in the world?

Answer 32

Above or below 35 degrees latitude

Question 33

biomarker for vit D

Answer 33

25-OH vit D

Question 34

level for 25-OH vit D that indicates deficiency risk

Answer 34

RDI: <30 nmol/L

Question 35

optimal level of 25-OH vit D

Answer 35

- RDI = 50 nmol/L - Canadian Osteoporosis = 75 nmol/L - GrassRoots Health = 100-150 nmol/L

Question 36

What is the link between vit D and athletic performance?

Answer 36

Correlation, but vit D is about as good as general health.

Question 37

Define: free radical

Answer 37

Capable of existence w/ unpaired electron

Question 38

1993 study found that vit C supplementation...

Answer 38

reduced incidence of post-race symptoms of URI infection in ultramarathon runners

Question 39

URI =

Answer 39

upper respiratory infection

Question 40

1996 study found that vit E supplementation...

Answer 40

reduced risk of cardiovascular death + non-fatal heart attack

Question 41

Vit C supplementation might be bad because (study findings)...

Answer 41

- Study found no change in damage/immune function with supplementation - Decrease muscle mitochondria biogenesis - Decrease endurance capacity (prevent cellular adaptation to exercise)

Question 42

Vit E supplementation might be bad because (study findings)...

Answer 42

- No improvement in performance | - Increased lipid peroxidation + inflammation during exercise

Question 43

Why might anti-oxidants be harmful?

Answer 43

Megadose of antioxidants => antioxidants become pro-oxidants

Question 44

What is lipid peroxidation

Answer 44

Free radical reaction involving lipids. Electrons stolen from lipids in cell membrane -> harmful

Question 45

When might antioxidant supplementation be ergogenic?

Answer 45

When you are deficient (e.g. vit C deficiency is scurvy)