Vitamins, Minerals and Antioxidants

Question 1

Describe the function of micronutrients:

Answer 1

▪ Micronutrients refers to the vitamins and minerals in foods and supplements
▪ We require them in much smaller amounts than the macronutrients
▪ They have several diverse functions in the body and aid in the absorption and metabolism of the macronutrients and support growth and development in various cells.
▪ They may also play a key role in supporting athletic performance
- Micronutrients will help you access the different macronutrients in the body

Question 2

Describe the function of vitamins:

What is the most known Vitamin deficiency?

Answer 2

▪ We can only synthesize a handful of vitamins in the body (vitamin D, vitamin K).
▪ Generally, we have to get vitamins from the foods that we eat
▪ There are 13 recognized vitamins - only found in the past 100yrs of research
▪ Most were discovered from deficiencies(Vit C), classic example being scurvy - discovered that sailors had the disease scurvy. - bleeding from gums, spongy teeth
When provided with a lime/lemon the scurvy would go away

Question 3

Describe the function of minerals:

Answer 3

▪ Inorganic compounds essential in many reactions and processes in the body
- Micronutrients do not provide energy
▪ Can be divided into macro-minerals and micro-minerals also known as trace elements
▪ Trace elements are needed in smaller amounts
▪ Do NOT provide energy; but many assist in metabolism, growth and development (Jeukendrup & Gleeson, 2011).

Question 4

Name and describe fat soluble vitamins:

Answer 4

ADEK vitamins are fat soluble vitamins, much easier to store
- Vit A - crucial for vision, is a component of rhodopsin(protein that absorbs and detects light in the eye) - deficiency is rare(xerophthalmia - inability to see in darkness), as found in most food
- Vit D - promotes bone growth and strength, regulates absorption of Calcium & phosphorus for good bone health, helps for muscle, heart and fighting infection. Deficiency is rickets

Question 5

Name and describe water soluble vitamins:

Answer 5

water soluble - not stored in body, disposed of through kidney(need to be replenished)
- B12,6,12
- Niacin, pantothenic acid, biotin, choline, Vit C
- Lack of Vit B12 can lead to anaemia
- Vit C leads to growth and repair of bones, teeth
UL - upper limit
Mainly found in “healthy” foods

Question 6

Name the main micro minerals and their function:

Answer 6

• iodine- component of thyroid hormones, common deficiency
• zinc- cofactor in over 100 proteins
• copper- component in several enzymes
• iron- essential for O2 transport
• fluoride- structure of bones, teeth

Question 7

What percentage of female endurance athletes are iron deficient?

Answer 7

15-20%

Question 8

What are the general roles of micronutrients in athletes?

Answer 8

▪ Growth and building new tissues
▪ For their role in antioxidants
▪ Oxygen transport
▪ Co-factors as enzymes
▪ Immune function

Question 9

What micronutrients are important for growth and building new tissues?

Explain

Answer 9

▪ Calcium
▪ Phosphorus
▪ Fluorine
▪ Vitamin D
▪ Vitamin C
▪ Calcium plays an important role in bone formation
▪ Deficiency can lead to osteoporosis (weak bones) and also stunted bone growth - benefit any athletes who have diet restrictions, endurance runners who load their bones
▪ Phosphorous also important for cell membranes
▪ Fluorine important for protection against tooth decay; could be even more important for athletes who regularly consume sugary rich-foods/drinks

Question 10

What micronutrients are important in oxygen transport?

Explain

Answer 10

▪ Iron
▪ Folic acid
▪ Phosphorus

▪ Oxygen carrying proteins, haemoglobin and myoglobin contain iron
▪ Iron deficiency can have important implications for those in endurance sports who rely heavily on muscle perfusion
▪ Iron deficiency not uncommon – 15-25% in females
- Excessive Iron intake promotes oxidative stress that compromises skeletal muscle function
▪ Folic acid (vitamin B12) important for blood cell production, helps with O2 delivery, so deficiency can cause fatigue
▪ Phosphorus helps support oxygen transport by encouraging O2 release into the local capillary networks

Question 11

What micronutrients are important cofactors in enzyme catalysed reactions?

Explain

Answer 11

▪ Iron
▪ Folic acid
▪ Phosphorus

▪ Oxygen carrying proteins, haemoglobin and myoglobin contain iron
▪ Iron deficiency can have important implications for those in endurance sports who rely heavily on muscle perfusion
▪ Iron deficiency not uncommon – 15-25% in females
- Excessive Iron intake promotes oxidative stress that compromises skeletal muscle function
▪ Folic acid (vitamin B12) important for blood cell production, helps with O2 delivery, so deficiency can cause fatigue
▪ Phosphorus helps support oxygen transport by encouraging O2 release into the local capillary networks

Question 12

What micronutrients are important for immune function?

Explain

Answer 12

▪ Vitamin A
▪ Vitamin C
▪ Vitamin E
▪ Vitamin B6, B12 and folic acid
▪ Zinc, iron, selenium, magnesium, copper

▪ AOX effects of vitamin A, C and E helps support immune function by reducing free radical accumulation
▪ Folic acid and B12 important for production of immune cells that fight off infections (WBC)
▪ Zinc an important co-factor for the production of several immune cells and is an AOX.
▪ Selenium helps synthesize the production of endogenous AOX systems, glutathione enzymes.
▪ Copper affects immune cell and anti-body development

Question 13

What micronutrients are important for electrolyte concentration?

Explain

Answer 13

▪ Sodium
▪ Potassium
▪ Chloride

▪ Sodium is important for maintaining water balance in cells and for nerve transmission and muscle contraction
▪ Potassium has similar functions as sodium; together they form the sodium-potassium pump.

Question 14

What micronutrients are important to maintain antioxidant concentrations?

Explain:

Answer 14

▪ Vitamin C
▪ Vitamin E
▪ Vitamin A (beta-carotene)
▪ Copper
▪ Selenium
▪ Manganese

Our bodies generate free radicals – they can damage cells and alter how they function; they are linked to various diseases

Molecules with antioxidant properties can stabilise free radicals(by providing an electron) – several 1000 work like this, key ones in the diet are Vit C, E and beta-carotene

Question 15

Do athletes need higher micronutrient intake?

Why is this the case?

Answer 15

• NO, if a healthy well balanced diet is ate. Some research that suprainterficial doses have a beneficial effect
  ▪ Most MNs can be got at the RDA level from a well-balanced healthy diet.
  ▪ Still, many athletes consume large amounts of vitamins and minerals in the hope that it will enhance performance
  ▪ Toxic effects possible if consumed in excess or at the very least negative performance effects
  ▪ Over the counter supplements that do not exceed the RDA can be recommended

Question 16

Why might an athlete need higher micronutrient intake in hot/humid conditions?

Answer 16

▪ Hot, humid environments/long duration exercise where sweat losses are high
▪ Magnesium, zinc, iron and sodium lost in greater quantities
▪ Moderately increase the quantities of these foods in the diet the day before, during and after exercise, e.g.: electrolytes

Question 17

Why might an athlete need higher micronutrient intake if they are vegan?

Answer 17

▪ Vegans at risk of vitamin B12 deficiency; cannot be obtained from non-meat sources
▪ Possibly also iron too; greatest source of heme iron, which is better absorbed from meat, thionine ingested from wheat intake can decrease iron absorption
▪ Zinc too as absorption can be lowered by fiber intake
▪ Vegan athletes might also require more calcium due to lack of dairy intake
▪ Calcium fortified products should be encouraged in the diet
▪ Nonheme iron sources should be encouraged (e.g., those in green leafy vegetables and legumes)
- Try to get the balance through diet, if not able to then use supplements

Question 18

Why might an athlete need higher micronutrient intake in weight making sports?

Answer 18

▪ Weight making sports such as MMA, boxing which might require excessive weight loss
▪ Low energy intake could lead to inadequate consumption of vitamins and minerals so supplement could be beneficial, to balance the energy deficiency
▪ Most important two are calcium and iron - beneficial to general health
▪ Again, food should be encouraged before supplementation

Question 19

Why might an athlete need higher micronutrient intake in Vitamin D deficient climates?

Answer 19

▪ Vitamin D deficiency possible in climates where there is a lack of sunshine - studies have shown that quite a lot of athletes are Vitamin D deficient
▪ If deficient, vitamin D fortified foods should be encouraged (e.g., cereals) - not able to extract the Vitamin D from foods, in comparison to sunlight
▪ A supplement should also be considered; levels need to be monitored regularly

Question 20

Why might an athlete need higher micronutrient intake after severe exercise?

Answer 20

▪ Severe exercise induced muscle damage (e.g., strength recovery not evident >7 days post) possible rationale for increased intake of antioxidant vitamins C & E. - May reduce delayed muscle soreness and severe muscle damage
▪ This can be achieved more safely through eating foods rich in these vitamins e.g., oranges and spinach

Question 21

Describe the Redox balance:

What is the optimal state?

Answer 21

• The balance between radicals(produced during exercise) and antioxidants(consumed from diet/supplementation)
• Continual production of these 3 radicles and continuous quenching of these 3 radicals
• The more difficult the exercise the more radicals produced
• A lot of endogenous antioxidants prevent the harmful effect of these radicals
  If we consume too many antioxidants(reductive stress) - overwhelming and not enough radicals
• We produce force at an optimal level of free radical production – too many and force production (e.g., exercise performance) is negatively affected

Question 22

Describe ROS:

What is superoxide?

What is the best method to measure ROS?

How can oxidative stress be induced?

Answer 22

ROS - Reactive oxygen species - first detected ROS was in skeletal muscle(the superoxide anion), this has a negative charge limiting transmembrane diffusion. Found in: myofiber cytosol, mitochondria, extracellular space and vascular compartment.
Strenuous exercise contractions cause fatigue increase superoxide concentrations(parent molecule of ROS) across all of these compartments, this reverses when contraction is ceased
* Superoxide’s are generated as a by-product of oxidative metabolism, due to incomplete reduction of molecular oxygen at CI and CII, also from NADPH oxidase
* ROS concentrations are better measured through biochemical markers as they are more stable
* Oxidative stress is induced by: altitude, hyperthermia, dehydration and osmotic stress

Question 23

What is oxidative stress?

What is reductive stress?

Answer 23

• when there is a higher concentration of antioxidants, compared to free radicals
• when there is a higher concentration of free radicals, compared to antioxidants

Question 24

How does the type of exercise impact the production of free radicals?

Answer 24

Muscles that are damaged also produce free radicals and therefore recovery could be delayed

ESR - direct production of free radicals

72hrs after exercise there was an increase in free radical production
Eccentric contractions tend to cause more muscle damage/ or running downhill

Question 25

What are polyphenols?

What is there function?

How might polyphenols affect performance?

Answer 25

Several foods contain (poly)phenols- more in brightly coloured fruit and veg (chemicals compounds) that have antioxidant functions (amongst others) and are therefore tested for their ability to enhance performance(clear moderate improvement) and speed up recovery – results are mixed!!
* Main polyphenol researched is quercetin
* Over 8000 identified polyphenols, main groups being: flavonoids, stilbenes, lignans and phenolic acids
* They stimulate stress-related cell signalling pathways, important for mitochondrial biogenesis and endurance performance, improve flow-mediated dilation and endothelial function(increasing NO synthesis
* Impact of Polyphenols on performance is measured through PO over time period and anaerobic threshold, Vo2max - but all studies have only been conducted on males

Question 26

What affect can Vitamin C & E have on training gains?

Answer 26

Oxidative stress is needed for the adaptations after
Exercise
- Vit C and E consumed in large amounts - cause reductive stress
- Trend that gains from Vit C&E of 8%, PLA gains were 12%. But not actually statistically significant
- Some suggestions that there may be a blunting effect on adaptations but not on muscle strength