Voeding en Gezondheid C
Module 1. Basic principles of micro nutrients
● Describe the basic features of vitamins and minerals
- micro nutrients: small amounts per day (<1g)
- macro nutrients provide energy, micronutrients do not. essential amino acids
and fatty acids are required in much larger quantities.
- Vitamins vs minerals
- Vitamins: organic molecules (contain chains of carbon atoms, complex
structure) For a normal metabolism, growth and maintaining good health
- Minerals: inorganic molecules (no carbon, mostly found in non living matters
eg. rocks)
- diseases cured with adequate diet: scurvy, rickets, beriberi and pellagra
● Understand the difference between fat-soluble and water-soluble vitamins
- Essential: humans do not produce them in sufficient amounts to meet the
normal needs.
- 13 groups of compounds are recognized as vitamins. Eg. vitamin E = group of
vitaminers with the parent compounds tocopherol and tocotrienol
- provitamin: compound that can be converted within the body to a vitamin
(carotenoids → vitamin A, retinol)
- Fat-soluble vitamins: A, D, E, K
1. more stable to heat (less likely to be lost during processing and
cooking foods)
2. absorbed from intestine with fats in food
3. first absorbed into lymph system then into blood
4. not soluble in blood, require specific carrier proteins
5. not excreted in the urine. Stored to a considerable extent in the body,
mainly liver and fatty tissues. Deficiency symptoms develop slowly.
Too much storage may lead to toxicity, (A, lesser in D)
- Water-soluble: C, B1 (Thiamin), B2 (Riboflavin), B3 (Niacin), B6, Folate, B12,
Biotin and Pantothenic acid.
Vitamin B12 is retained in the body quiet well, causes intoxication
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● Understand the difference between minerals and trace elements
- dietary mineral: encompasses the chemical elements that are essential for the
human body
- 21 elements are essential components of our diet. (carbon, hydrogen,
nitrogen and oxygen, are deducted from organic molecules)
- the 17 elements left comprise the dietary minerals.
- Major mineral: present in the body in excess of 5g
calcium, phosphorus, potassium, sulfur, sodium, chloride and magnesium
- Trace elements:
, iron, zinc, copper, manganese, molybdenum, fluoride, cobalt, iodine, selenium
and chromium.
- may be trace elements: Boron and silicium
- All the other elements are non-essential. May be relatively harmless (helium)
or extremely toxic (polonium, plutonium)
- only part of the total amount of minerals in a food is available: minerals are
bound to compounds that limit their absorption. Compounds: phytates,
polyphenols, oxalate and dietary fiber. (= bioavailability)
- Bioavailability is lower in plant-foods, . The total mineral intake can meet the
recommendation but there’s still a poor mineral status.
- low mineral bioavailability can be caused by processing and/or preparing
food.
● Describe the purpose of the Dietary Reference Intake (DRI), its components and how
the DRI is determined
- Vit C 60 mg/day, calcium 1000 mg/day
- estimated average requirement + recommended dietary allowance +
adequate intake + the tolerable upper intake level
-
- DRIs provide scientific basis for the development of food guidelines
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● To have insight into which groups or individuals may benefit from vitamin and/or
mineral supplements
- Newborns: oral dose or shot of vitamin K to prevent bleeding. Breastfed
babies should be given vitamin K supplemental up to 3 months. Vit K + D is
added to formula for bottle-fed babies.
- Vitamin D: Babies up to 1 year should supplement vit D when not bottle-fed,
males older than 70, females older than 50, pregnant women, people that
rarely go outside, people that cover their skin and dark-skinned people.
- Calcium: elderly + populations where calcium intake is low (prevention of
pre-eclampsia)
- B12: elderly + vegan/vegetarians
, - Iron: vegetarians + women of childbearing age + pregnant women
- Folate: pregnant women four weeks prior to and eight weeks after conception.
- Newborns: vitamin K, vitamin D;
- pregnant women: folate and iron, vitamin D as well and maybe calcium;
- elderly : vitamin D, vitamin B12, maybe calcium;
- vegans : vitamin B12 and iron, at least females should.
- Beter goede voeding dan supplementen: foods have much more to offer
various bioactive compounds and dietary fiber. + foods are tasty and provide
pleasure
- Strictly it doesn’t matter whether you get your micronutrients from
supplements of from real meals
Module 2: Water, Minerals and Trace Elements
● To describe the main sources of water intake, the main roles of water in our body, the
main routes of water loss and understand the concept of water balance
- men 60%, women 50% water, depending on body fat percentage.
- Water intake: water, other liquids, solid foods
- Fruits, vegetables and various beverages (milk, fruit juice, soda) contain 80%
of water. Potato chips, crackers and chocolate: 10%
- Total water intake 2 liters a day
- Water loss: urine (amounts adjust to maintain water balance), sweat (100 ml
to 5L, depending on mostly climate and less strenuous physical activity),
exhaled air (300 to 400 mL), stools (150mL)
- water loss → no compensation → dehydration
- Kidneys → renin-angiotensin system → excess production of urine when fluid
ingestion is high → not enough under extreme conditions
- dehydration becomes life-threatening >10% of body weight. → excess
vomiting, diarrhea, use of drugs, decreased water intake.
- Water overdose = water intoxication → provokes disturbance in electrolyte
balance and gives rise to neurological symptoms.
- Bottled water: Spa (belgium) and Evian (france) have a low to very low
mineral content. Other mineral waters such as San Pellegrino or Contrex
have high mineral levels. The last ones can contribute to the daily mineral
intake
- Tap Water: situation is different in developed and underdeveloped countries.
Mineral contents are higher than spa but lower than expensive European
brands of mineral water. There are no solid reasons to favor bottled water
over tap water
● To be able to better judge health claims made about water
, -there is no evidence for health claims about water such as: weight loss,
muscle growth, sexual performance etc.
- there are some leads for decreases in health related to low water intake such
as kidney failure and hyperglycemia.
- there is no harm in drinking plenty of water throughout the day, except extra
bathroom visits HA HA HA
● To be able to define dietary minerals, to recite the main dietary minerals
● To describe the main roles of sodium and potassium, to appreciate the rationale for
salt restriction
- 40% van NaCl is sodium. 75% of daily sodium intake comes from processed
foods, 15% comes from added salt during cooking.
- Most accurate method for estimating sodium intake: measuring total urinary
excretion of sodium.
- Potassium is present in large amounts of whole foods.
- Most diets include lots of processed foods, therefor people eat more sodium
than needed.
- Salt (Sodium). Recommendation = 5g/day (2g/day), mean intake =
10g/day(4g/day).
- high sodium intake → raise blood pressure (major risk cardiovascular
disease. and kidney disease) hard to give solid evidence, no studies where
salt restriction is the only variable. Studies in America show reducing salt
intake can cause harm (losers). There is uncertainty about the target value for
daily sodium intake.
- Function:
Potassium, main cation (ion that carries a proton) inside cells. Sodium, main
cation outside cells.
Difference of concentration in and outside of the cell = difference in charge=
membrane potential.
- needed for: transmission of impulses along nerves, muscle
contraction, heart function and release of hormones from cells.
- ⅓ of fluid in the body is outside the cells: blood or interstitial fluid. Sodium and
potassium concentration play an important role in the distribution of fluid. Changes in
concentration lead to fluid build-up in tissues = edema
- The bottom line: at the current level of intake in nearly all countries in the world, reducing
sodium intake in the population is expected to substantially reduce the number of deaths
from cardiovascular disease and other diseases, and thus provides clear justification for the
salt reduction programmes initiated in numerous countries.
- lowering salt intake: 1) reduce salt levels in processed foods in small steps 2) replace
chloride by potassium 3) reduce the need for added salt, by increasing the amount of spices.
- The oral sensation of salt is more pronounced when salt is divided unevenly. Therefor salt
levels can be lowered, without compromising the salt sensation.
● To know the dietary sources of calcium, to gain insight into the function of calcium in
the body, and the relation to human health
