Vitamins

Question 1

Vitamins are important for RBC formation, nucleotides for DNA, neurotransmitters, strong bones.. What vitamins do we need for these processes?

Answer 1

RBC formation: we need B-vitamins (B6, 12, folate): to make nucleotides for DNA
Neurotransmitters: we need B12
Strong bones: B,C (collagen), ETC.

Question 2

What is an important cycle for B-vitamins?

Answer 2

methionine cycle

Question 3

The methionine cycle is metabolically connected with the A. Vit B is needed for the conversion of B into C. Otherwise, problems with the D arise. Then you cannot make enough E, then RBC are not able to F

Answer 3

A folate metabolism
B Homocysteine
C methionine
D CNS
E DNA
F Divide (anaemia)

Question 4

What is the best B6 status assessment?

Answer 4

• Whole blood/red blood cell B6: best mid-term indicator, not sensitive for inflammatory status (~50-180 nmol/L)
• Plasma/serum values significantly lower than whole blood levels!

Question 5

Why do some tests for B6 status not indicate an intoxication, when in fact there is an intoxication?

Answer 5

Because there are 6 vitamin B6 vitamers:

• PLP is biologically active B6 vitamer!
• Most tests measure only PLP (routine labs), full B6 profile not common (research labs only)
• Might be intoxicated with the other monomers, but not PLP, which is the only one to show up on the test

Question 6

How can folate be assessed?

Answer 6

• Plasma/serum folate: most widely used marker, ‘short term’
• Whole blood/red blood cell folate: best mid-term indicator, but laborious and prone to error (depends on Ht measurement), red blood cell = can be 100 days old (look back in time)
• ‘Total folate’ test most common in routine labs
• ‘gold standard’ microbial assay, but sensitive to e.g. antibiotic treatment
  And more

Question 7

How can B12 be assessed and what is an issue?

Answer 7

Direct plasma/serum B12 analysis (~ 200/300–600 pmol/L)
● Functional markers (holo-TC or methylmalonic acid) better than B12?
● Lack of standardisation between different B12 tests! Different results from different labs

Question 8

What are deficiency signs of B6?

Answer 8

neurological dysfunction

Question 9

What are deficiency signs of folate?

Answer 9

anemia, fatigue

Question 10

What are deficiency signs of B12?

Answer 10

anaemia, fatigue, cognitive impairment

Question 11

What are deficiency signs of vit D?

Answer 11

weak bones/fractures
- Deficiency increases risk of autoimmune diseases and can have profound effect on human immunity, inflammation, muscle function

Question 12

Which is likely to be a public health concern?
B6, Folate, B12, D

Answer 12

Folate, vit D

Question 13

Why does exercise not increase your vitamin requirements?

Answer 13

Vitamins are often co-factors and not usually lost during exercise.

Question 14

What is a common statement about vit B which is not true?

Answer 14

‘All B-vitamins are excreted by the urine anyways’ they are water-soluble but this is not true: still toxic.

Question 15

Are there vit B recommendations for the athletes? What are risk groups?

Answer 15

• With a balanced diet, no immediate concern for B-vitamin deficiencies
• Risk groups for deficiency: dietary restrictions, vegans (B12), use of certain medication (e.g. proton pump inhibitors, metformin)

Question 16

Vit D: - Deficiency increases risk of autoimmune diseases and can have profound effect on human immunity, inflammation, muscle function. What is the accepted status marker for vit D?

Answer 16

25(OH)D = accepted status marker (25-hydroxy vitaminD3) in blood

Question 17

It is estimated that X% = insufficient/deficient 25 (OH)D level at baseline (end of winter season). Fluctuation during seasons. Outdoor exercise elevates vitamin D levels

Answer 17

70%

Question 18

What are some genomic and non-genomic functions of Vit D + muscle?

Answer 18

Genomic events
● Nuclear receptor
● Gene transcription and protein synthesis
● Muscle cell proliferation and calcium uptake

Non genomic events
● Calcium uptake sarcolemma
● MAPK signalling pathways

Question 19

At what concentrations can you get hypercalcaemia?

Answer 19

(> 100 μg/day for extended
periods), but this intoxication from excess supplementation is very rare

Question 20

Recommendations vit D?

Answer 20

• Stimulate outdoor exercise! (but consider skin cancer risk!)
• Screen athletes
  ● At least biannualy: late summer, winter
  ● history bone injury, frequent illness, restrained eating and indoors; strict vegetarians
• Correct deficiencies (< 75 nmol/L)
• D3 slightly more effective than D2
• Dose
  ● Sun exposure
  ● 100 IU increases serum 25(OH)D ~2.5 nmol/L
  ● > 10.000 IU/day toxicity

Question 21

ROS: the good and bad part?

Answer 21

Good: oxidative stress is a key ‘signal’ to promote adaptation & training (as well as to activate DNA repair mechanisms etc

Bad:
* Leads to cellular damage: DNA, proteins, lipids, Etc

Question 22

Immune cells can also make ROS. Its function is..

Answer 22

against microbes

Question 23

Recall three antioxidant vitamins

Answer 23

A,E,C (amongst others?)

Question 24

Recall three endogenous zntioxidant systems with examples

Answer 24

Nonenzymatic systems
● Glutathione, bilirubine, coenzyme Q10
Enzymatic systems → detoxification
● Superoxide dismutase (SOD), glutathione peroxidase, catalase, etc.
Dietary factors! → scavenging
● Vitamin C, vitamin E, carotenoids, polyphenols

Question 25

Why is it good to be careful with reducing oxidative stress?

Answer 25

• Some studies say that it hampers cellular adaptation to endurance training

Question 26

Connect the right nutrient to the right words

1. CH
2. HFLC
3. Protein
4. Fluid
5. Micronutrients
6. Ergogenic aids

A winning edge
B stay hydrated
C prevent deficiencies
D training adaptation -> reduce CH reliance
E skeletal muscle reconditioning
F fueling HI exercise

Answer 26

1 F
2. D
3. E
4. B
5. C
6. A