Minerals

Question 1

What sports are at risk for mineral deficiencies and what is the cause?

Answer 1

Gymnast,jockey,ballet,dancing: low BW, low EI
Weight-class sports (rowing, judo, wrestling): competition weight
Body building: low-fat, drastic weight loss
(female) endurance athletes: vegetarian diets
Endurance events: Training in hot/humid conditions

Question 2

Iron is a very toxic element (ROS) true/false

Answer 2

true

Question 3

In what sources does iron come?

Answer 3

Haem-iron vs non-haem-iron

Question 4

What type of charged state does iron have and when can the body directly use it?

Answer 4

Fe2 used, like incorporated in membranes
Fe3 will have to be changed first

Question 5

Absorption of iron in the intesine is..

Answer 5

poor (10%). Increases when deficient.

Question 6

Learn the scheme on p. 93. Ferritin = ?
Ferroportin = ?
Transferrin = ?
Hepcidin = ?

Answer 6

• Ferritin = cellular protein that stores iron, important marker. Bit of spillover in the blood
• Ferroportin (Fpn) = transporter in cellular membranes (inside cell -> outside)
• Transferrin = transport protein in blood
• Hepcidin = important for exrcise, can block activity of ferroportin

Question 7

What happens when there is too long activity of hepcidin?

Answer 7

Hepcidin activity for too long: may become aenemic, even though you ingest enough iron

Question 8

When is hepcidin upregulated?

Answer 8

in response to inflammation, infection. Will keep iron in cells so it is not available for bacteria. Also upregulated by exercise (exercise -> inflammation).

Question 9

What is assessed as iron status with haemoglobin, ferritin, transferrin?

Answer 9

▪ Haemoglobin: ‘functional’ iron
▪ Ferritin: iron storage
▪ Transferrin: iron transport

Question 10

How are stages of iron deficiency defined?

Answer 10

Early stage: decrease ferritin
Intermediate stage: transferrin decrease
Late stage: haemoglobin decrease, altered RBC volume parameters

Question 11

Iron deficiency is common/uncommon

Answer 11

uncommon

Question 12

Symptoms of iron deficiency?

Answer 12

▪ Weakness, breathlessness, impaired aerobic capacity
▪ Non-specific symptoms

Question 13

Effect of iron on aerobic capacity / performance:

Answer 13

● Iron depletion: no effect on aerobic capacity (VO2max)
● Iron deficiency anaemia: clear impairment

Question 14

Recall some reasons why there is an increased iron requirement in athletes

Answer 14

• Increased requirement: red cell mass
• Sweat loss
• loss due to haemolysis
  (urine, GI-bleeding, mechanical forces)

Question 15

Iron is highly toxic, what are some side-effects?

Answer 15

constipation, black stools, abdominal cramping

Question 16

Calcium status in blood: reliable measure?

Answer 16

No, does not say much

Question 17

Vit D is needed for calcium uptake. Without it: risk for..

Answer 17

Stress fractures . History of one or more stress fractures = significant.

• Calcium ‘not a significant risk factor’, apparently. However supplementing vit D and calcium reduced incidence of stress fractures.

Question 18

How can you get enough calcium from the diet, even on a restricted diet?

Answer 18

▪ Include three servings per day low-fat dairy
▪ Include these dairy foods in high-CHO meals
▪ Eat fish with bones
▪ Include Ca-enriched soy products
▪ Eat leafy green vegetables

Question 19

Magnesium is needed for about …. processes in the human body

Answer 19

> 600

Question 20

Magnesium is important for these processes (4): (among others)

Answer 20

• Energy metabolism
• DNA replication
• Formation bone tissue
• Nerve conduction & muscle function

Question 21

What are deficiency symptoms for magnesium?

Answer 21

▪ Muscle spasms
▪ Cardiovascular disease
▪ Osteoporosis
▪ Caused by poor intake, disturbed digestion (e.g. polypharmacy: taking medicine), or excessive excretion (e.g. kidney disease)

Question 22

What is good to take into account when measuring magnesium status?

Answer 22

All kinds of exercise have different effects on magnesium concentrations. Temporary metabolic response due to exercise-induced stress: low magnesium. But after exercise, the values increase again. But also when doing the same exercise on day 1, 2, 3, 4. There will be decrease on day 1, then it is stable again: your body adapts.

Question 23

There are no sports-specific recommendations for iron or magnesium

Answer 23

true!

Question 24

Zinc: what is it?

Answer 24

Component of enzymes involved in muscle energy production and protein synthesis

Question 25

What decreases plasma zink and what is the risk with increased intake?

Answer 25

1. stress
2. CVD

Question 26

Why is there an increased requirement for athletes for selenium/copper?

Answer 26

▪ Increased requirement through free radical formation during exercise
▪ Increased loss via sweat and urine

Question 27

Are there sports-specific recommendations for selenium/copper?

Answer 27

No. Main message: general recommendations for micronutrients are working well for athletes