MOOC Undernutrition
Contents
Dietary References intakes (DRI).........................................................................................................4
Estimated Average Requirement (EAR)...............................................................................................5
Recommended Dietary Allowances (RDA)...........................................................................................5
Adequate Intake (AI)............................................................................................................................5
Tolerable Upper Intake Level (UL).......................................................................................................6
Additional information on Dietary Reference Intakes .........................................................................6
Dietary supplements................................................................................................................................6
Harm of Supplements..............................................................................................................................6
Module 2................................................................................................................................................6
Dehydration.............................................................................................................................................8
Sodium and potassium............................................................................................................................9
Salt restriction programs...................................................................................................................10
Function.............................................................................................................................................11
Blood pressure...................................................................................................................................11
Vascular calcification.........................................................................................................................11
Obesity...............................................................................................................................................11
Iron........................................................................................................................................................12
Absorption.........................................................................................................................................12
Storage...............................................................................................................................................12
Function.............................................................................................................................................13
Health effects of iron.........................................................................................................................13
Iodine.....................................................................................................................................................14
Iodine deficiency................................................................................................................................14
Other food sources............................................................................................................................14
Selenium................................................................................................................................................14
Function in the body..........................................................................................................................14
Proteins and zinc....................................................................................................................................15
Module 3..............................................................................................................................................16
Vitamin A...............................................................................................................................................16
Forms of vitamin A in the body..........................................................................................................16
1
, Food sources and DRI of vitamin A....................................................................................................16
Functions of vitamin A...........................................................................................................................17
Vitamin A in vision.............................................................................................................................17
Vitamin A deficiency and toxicity.......................................................................................................18
Vitamin D...............................................................................................................................................18
Functions of vitamin D.......................................................................................................................19
Vitamin D deficiency and toxicity.......................................................................................................19
Measuring vitamin D..........................................................................................................................20
Vitamin E................................................................................................................................................20
Vitamin E deficiency and toxicity.......................................................................................................21
Vitamin K...............................................................................................................................................21
Vitamin K deficiency..........................................................................................................................21
Module 4 Water-soluble vitamins........................................................................................................22
Vitamin C deficiency and toxicity.......................................................................................................23
Folate.....................................................................................................................................................23
Metabolism........................................................................................................................................24
Vitamin B12...........................................................................................................................................25
The remaining B vitamins......................................................................................................................26
Thiamin (vitamin B1)..........................................................................................................................26
Riboflavin (vitamin B2).......................................................................................................................26
Niacin (vitamin B3).............................................................................................................................26
Pantothenic acid................................................................................................................................27
Vitamin B6.........................................................................................................................................27
Biotin.................................................................................................................................................27
Module 1
Micronutrients: Need to consume less than 1 gram per day
- Essential Minerals: (inorganic molecules= does not contain carbon) Rock
- Major minerals
Present in body in excess of 5g
In order of abundance: calcium, phosporus, potassium, sulfur, sodium, chloride
and magnesium
- Trace elements
iron, zinc, copper, manganese, molybdenum, fluoride, cobalt, iodine, selenium
and chromium
- Vitamins (organic molecule= contains carbon atom) Organisms
- Fat soluble vitamins (vit: A, D, E, K)
2
, - More stable to heat, less likely to be lost during cooking
- Absorbed in intestine along with fats
- Absorbed into the lymph system and then into the blood
- Not soluble in blood (need carries molecules)
- Stored in the body (liver and fatty tissue)
- Water soluble vitamins (vit. B + C)
- Poorly retained by the body excreted via the urine
- Need to be eaten regularly (no storage), but less likely toxic
- Exception: B12 is retained in the body
Insufficient intake may lead to specific deficiency syndrome
Vitamers: Same vitamin family of chemically related compounds with comparable metabolic activities
Provitamin: compound that can be converted within the body to a vitamin
Macronutrients: Need to consume larger quantities, and provide energy
- Essential amino acids
- Fatty acids
Mineral bioavailability
Only a part of the total amount of minerals present in a food is available to the body. That is mostly
because minerals are bound to compounds in the foods that limit their absorption.
Bioavailability: the extent to which ingested minerals or other food components are absorbed and
thereby available to the body.
In low-income countries, a low bioavailability of minerals is a major contributor to poor mineral
status. This situation is mainly observed in people subsisting on monotonous plant-based diets.
Plant foods have a lower mineral bioavailability compared to animal foods. Diet-related factors
in plant foods that affect bioavailability include the chemical form of the nutrient in food and/or
nature of the food matrix. In addition, many plant foods are rich in negatively charged
compounds that tightly bind cations (positively charged elements such as calcium, iron and
zinc) and thus have lower mineral bioavailability. These compounds include phytates,
polyphenols, oxalate, and dietary fiber. Finally, low mineral bioavailability may be caused by
pre-treatment of a food as a result of processing and/or preparation practices.
Dietary minerals are present in nearly all foods. Except in vegetable oils and table sugar. Much
of our calcium intake comes from eating cheese and milk, whereas most of the dietary iron is
obtained via consumption of whole grain products, beans, and meat.
Discovery of Vitamins:
Diseases could be caused when food lacked a substance necessary for metabolism.
The term ‘vitamin’ was coined by Funk in 1912 when he isolated the anti-beriberi factor.
Hopkins established that rats got sick and died when put on diets of pure protein, fat and
carbohydrates. The addition of milk made the difference between life and death for the rats.
McCollum and his coworker Kennedy proposed the terms “fat-soluble A” and “water-soluble B”
3
Contents
Dietary References intakes (DRI).........................................................................................................4
Estimated Average Requirement (EAR)...............................................................................................5
Recommended Dietary Allowances (RDA)...........................................................................................5
Adequate Intake (AI)............................................................................................................................5
Tolerable Upper Intake Level (UL).......................................................................................................6
Additional information on Dietary Reference Intakes .........................................................................6
Dietary supplements................................................................................................................................6
Harm of Supplements..............................................................................................................................6
Module 2................................................................................................................................................6
Dehydration.............................................................................................................................................8
Sodium and potassium............................................................................................................................9
Salt restriction programs...................................................................................................................10
Function.............................................................................................................................................11
Blood pressure...................................................................................................................................11
Vascular calcification.........................................................................................................................11
Obesity...............................................................................................................................................11
Iron........................................................................................................................................................12
Absorption.........................................................................................................................................12
Storage...............................................................................................................................................12
Function.............................................................................................................................................13
Health effects of iron.........................................................................................................................13
Iodine.....................................................................................................................................................14
Iodine deficiency................................................................................................................................14
Other food sources............................................................................................................................14
Selenium................................................................................................................................................14
Function in the body..........................................................................................................................14
Proteins and zinc....................................................................................................................................15
Module 3..............................................................................................................................................16
Vitamin A...............................................................................................................................................16
Forms of vitamin A in the body..........................................................................................................16
1
, Food sources and DRI of vitamin A....................................................................................................16
Functions of vitamin A...........................................................................................................................17
Vitamin A in vision.............................................................................................................................17
Vitamin A deficiency and toxicity.......................................................................................................18
Vitamin D...............................................................................................................................................18
Functions of vitamin D.......................................................................................................................19
Vitamin D deficiency and toxicity.......................................................................................................19
Measuring vitamin D..........................................................................................................................20
Vitamin E................................................................................................................................................20
Vitamin E deficiency and toxicity.......................................................................................................21
Vitamin K...............................................................................................................................................21
Vitamin K deficiency..........................................................................................................................21
Module 4 Water-soluble vitamins........................................................................................................22
Vitamin C deficiency and toxicity.......................................................................................................23
Folate.....................................................................................................................................................23
Metabolism........................................................................................................................................24
Vitamin B12...........................................................................................................................................25
The remaining B vitamins......................................................................................................................26
Thiamin (vitamin B1)..........................................................................................................................26
Riboflavin (vitamin B2).......................................................................................................................26
Niacin (vitamin B3).............................................................................................................................26
Pantothenic acid................................................................................................................................27
Vitamin B6.........................................................................................................................................27
Biotin.................................................................................................................................................27
Module 1
Micronutrients: Need to consume less than 1 gram per day
- Essential Minerals: (inorganic molecules= does not contain carbon) Rock
- Major minerals
Present in body in excess of 5g
In order of abundance: calcium, phosporus, potassium, sulfur, sodium, chloride
and magnesium
- Trace elements
iron, zinc, copper, manganese, molybdenum, fluoride, cobalt, iodine, selenium
and chromium
- Vitamins (organic molecule= contains carbon atom) Organisms
- Fat soluble vitamins (vit: A, D, E, K)
2
, - More stable to heat, less likely to be lost during cooking
- Absorbed in intestine along with fats
- Absorbed into the lymph system and then into the blood
- Not soluble in blood (need carries molecules)
- Stored in the body (liver and fatty tissue)
- Water soluble vitamins (vit. B + C)
- Poorly retained by the body excreted via the urine
- Need to be eaten regularly (no storage), but less likely toxic
- Exception: B12 is retained in the body
Insufficient intake may lead to specific deficiency syndrome
Vitamers: Same vitamin family of chemically related compounds with comparable metabolic activities
Provitamin: compound that can be converted within the body to a vitamin
Macronutrients: Need to consume larger quantities, and provide energy
- Essential amino acids
- Fatty acids
Mineral bioavailability
Only a part of the total amount of minerals present in a food is available to the body. That is mostly
because minerals are bound to compounds in the foods that limit their absorption.
Bioavailability: the extent to which ingested minerals or other food components are absorbed and
thereby available to the body.
In low-income countries, a low bioavailability of minerals is a major contributor to poor mineral
status. This situation is mainly observed in people subsisting on monotonous plant-based diets.
Plant foods have a lower mineral bioavailability compared to animal foods. Diet-related factors
in plant foods that affect bioavailability include the chemical form of the nutrient in food and/or
nature of the food matrix. In addition, many plant foods are rich in negatively charged
compounds that tightly bind cations (positively charged elements such as calcium, iron and
zinc) and thus have lower mineral bioavailability. These compounds include phytates,
polyphenols, oxalate, and dietary fiber. Finally, low mineral bioavailability may be caused by
pre-treatment of a food as a result of processing and/or preparation practices.
Dietary minerals are present in nearly all foods. Except in vegetable oils and table sugar. Much
of our calcium intake comes from eating cheese and milk, whereas most of the dietary iron is
obtained via consumption of whole grain products, beans, and meat.
Discovery of Vitamins:
Diseases could be caused when food lacked a substance necessary for metabolism.
The term ‘vitamin’ was coined by Funk in 1912 when he isolated the anti-beriberi factor.
Hopkins established that rats got sick and died when put on diets of pure protein, fat and
carbohydrates. The addition of milk made the difference between life and death for the rats.
McCollum and his coworker Kennedy proposed the terms “fat-soluble A” and “water-soluble B”
3
