Vitamins and Hydration

Question 1

Vitamins?

Answer 1

Organic substances (i.e. containing carbon atoms) needed in very small amounts to perform specific metabolic functions. Vitamins typically act as coenzymes, facilitating numerous reactions in the body.

Question 2

Water Soluble Vitamins?

Answer 2

Includes B and C vitamins that dissolve in water and are transported in blood. With the exception of B12, which is stored in the liver for years, water-soluble vitamins are not stored in appreciable amounts in the body; the body uses what is needed and then excretes the rest in the urine.

Question 3

Fat Soluble Vitamins?

Answer 3

A, D, E, K.

Question 4

Vitamin A?

Answer 4

Excess is toxic and associated with liver damage, intracranial pressure, dizziness, nausea, headaches, skin irritation, pain in joints, coma, and even death. Usually occurs through high level of supplements, not from diet.

Question 5

Vitamin D?

Answer 5

High levels can lead to arrhythmias and increased levels of blood calcium, which can cause blood vessel and tissue calcification, as well as damage to the heart, blood vessels, and kidneys.

Question 6

Vitamin E?

Answer 6

Acts as an anticoagulant and thins the blood, high levels are associated with hemorrhagic stroke, particularly in individuals who are on blood thinners.

Question 7

Vitamin K?

Answer 7

This helps clot blood and can interfere with some anticlotting medications.

Question 8

Minerals?

Answer 8

Contribute to the structure of bone, teeth, and nails; are a component of enzymes; and perform a wide variety of metabolic functions.

Question 9

Calcium?

Answer 9

Needed for bone and tooth formation/function, nerve transmission, blood vessel contraction/expansion, hormone/enzyme secretion, and muscle contraction. When calcium intake falls short the body pulls it from bone to maintain concentrations in the blood, muscle, and intracellular fluids.

Question 10

Iron?

Answer 10

Essential for both the functioning and synthesis of hemoglobin, a protein that transfers oxygen throughout the body. Iron is also a component of myoglobin, which transports oxygen to muscles. Also plays a role in growth, development, cell functioning, and the synthesis/function of some hormones.

Question 11

Iron Deficiency?

Answer 11

Iron deficiency is the most prevalent nutrition deficiency in the world. Occurs in 3 stages: depletion, marginal deficiency, and anemia. Iron carries oxygen to muscles and even marginal iron deficiency may impair athletic performance. Symptoms include weakness, fatigue, poor concentration, headache, decreased exercise capacity, hair loss, and dry mouth. Other symptoms include feeling cold often, inflamed tongue, shortness of breath during routine activities, and pica (desire to eat nonfood substances). Women of childbearing age and younger are at greatest risk. Also, distance runners, vegetarian athletes, those who bleed a lot during cycles, those taking a lot of antacids, and those with certain digestive diseases such as celiac at increased risk.

Question 12

Types of Iron?

Answer 12

Heme and nonheme. Heme, derived from hemoglobin is found in foods containing hemoglobin and myoglobin – animal foods. Heme is better absorbed than nonheme (we absorb 15-35% of heme iron and 2-20% of nonheme iron we eat). Nonheme is in non-meat foods.

Question 13

Absorption of Iron?

Answer 13

Consume vitamin-C rich foods/beverages at the same as a nonheme iron source or consume heme and nonheme together to increase absorption. Calcium and magnesium can interfere with iron absorption though.

Question 14

Major Minerals?

Answer 14

Calcium, phosphorus, magnesium, iron, and the electrolytes sodium, potassium, and chloride.

Question 15

Percentage of Body is Water?

Answer 15

45-75%

Question 16

Sweat losses that exceed fluid intake?

Answer 16

Leads to hypohydrated state with subsequent increase in core body temperature, decrease in blood plasma volume, and increase in heart rate and perceived exertion.

Question 17

Hot environments and exercise?

Answer 17

Repeated exercise in hot environments helps the body adapt to heat stress (greater sweat volume, lower electrolyte concentration of sweat, and lower temperature at the onset of sweating) and therefore athletes may be more prone to dehydration and heat stress at the beginning of the season.

Question 18

Mild dehydration?

Answer 18

Even mild dehydration, representing 2-3% weight loss, can increase core body temperature and significantly affect athletic performance by increasing fatigue and decreasing motivation, neuromuscular control, accuracy, power, strength, muscular endurance, and overall performance.

Question 19

AI for water?

Answer 19

The AI for water is 3.7 L for men and 2.7 L for women. This includes all sources of fluid including coffee, tea, juice, soda, and fluid in food.

Question 20

What percentage water losses should we try to prevent?

Answer 20

Anything exceeding 2% of body weight.

Question 21

How can you assess hydration status?

Answer 21

Urine specific gravity is good for chronic hydration status. This is not a good test of acute changes. In order to assess hydration status acutely, look at weight before and after workouts (with minimal clothing, sweaty clothing should be removed as well). Each pound lost represents 16 ounces or about 0.5 Liters.

Question 22

How to assess sweat rate?

Answer 22

Pre-exercise body weight – post-exercise body weight + fluid intake during exercise – urine produced

Question 23

Problems with USG?

Answer 23

When athletes consume large quantities of fluid they produce copious amounts of urine long before they become adequately hydrated.

Question 24

Major electrolytes lost in sweat?

Answer 24

Sodium, chloride, and to a lesser extent and in order, potassium, magnesium, and calcium.

Question 25

Role of sodium?

Answer 25

Influences fluid regulation by helping retain more of the fluid consumed.

Question 26

Salt and hydration?

Answer 26

Given the large quantity of sodium some athletes lose through sweat, replacing sodium/electrolytes may be necessary. Athletes who exercise for long periods and only hydrate with water or low-sodium beverages may dilute their blood sodium levels to dangerously low levels, know as hyponatremia.

Question 27

How to avoid hyponatremia?

Answer 27

Don’t allow fluid intake to exceed sweat losses. Athletes shouldn’t weigh more after they finish exercising compared to when they start and they should also consume sodium through their sports drink or food.

Question 28

Thirst and regulation of hydration?

Answer 28

Thirst may not be a reliable indicator of fluid needs for athletes who are heavy sweaters or those who practice intensely in hot environments.

Question 29

USG Readings?

Answer 29

Less than 1.020

Question 30

Fluid intake for children?

Answer 30

Children weighing 88 pounds should drink 5 ounces, and adolescents 132 pounds should drink 9 ounces, of cold water or a flavored, salted beverage every 20 minutes.

Question 31

Fluid intake for adults?

Answer 31

Should be individualized. During prolonged activity in hot weather, they should consume a sports drink containing 20 to 30 mEq of sodium, 2 to 5 mEq of potassium, and carbohydrate in a concentration of 5-10%.

Question 32

Fluid intake after training?

Answer 32

If dehydration is significant or the athlete has <12 hours before the next exercise bout, a more aggressive approach is warranted and the athlete should consume approximately 1.5 L of fluid with sufficient electrolytes for each Kg of body weight lost.