Water and minerals Ahmad Albalawi Lecturer and senior specialist in Nutrition

Outlines Water and the Body Fluids Sources Requirements References

Water and fluids 50-70% of the body is fluid fluid content differs among tissue: – muscle tissue ~ 70% fluid – fat tissue ~ 10-20% fluid therefore: – leaner people - proportionally more fluid – total body fluid is lower in females – total body fluid decreases with age

Sources Food sources: – solid foods contribute ~20% intake – ~250 ml produced by metabolism – remainder from free water and/or other fluids

Sources Balance of water Fluid Input: – beverages – food – metabolic water Fluid Output: – Urine – Faeces – insensible evaporation – from lungs – sweat

Requirements specific to each individual – influenced by: – age – body size – health status – environmental conditions – physical activity level – Individual metabolism

Requirements Fluids (plain water, milk and other drinks) Total Water (food and fluids) 2.6 L/day(10 cups)3.4 L/dayMen L/day (8 cups)2.8 L/dayWomen 19+

Requirements excess water intake can cause hyponatraemia but occurrence is rare in general population

References Dudek, S.G (2006). Nutrition essential for Nursing Practice. 5 th edition, Lippincott, Philadelphia, USA. Whitney, W & Rolfes, SR (2008) Understanding Nutrition (11 th ed), Thomson Higher Education, Belmont, CA, USA.

Major minerals

Outlines Overview Major and minor minerals Sources Roles in the body Dietary recommendations and management Deficiencies and toxicities Referecnes

Overview Minerals are inorganic elements that originate from the earth’s crust, not from plants or animals

Major and minor minerals Major minerals Calcium Phosphorus Magnesium Sulfur Sodium Potassium Chloride Minor minerals – Iron – Iodine – Zinc – Selenium – Copper – Manganese – Fluoride – Chromium – Molybdenum

Sources Food – Unrefined or unprocessed foods have more minerals than refined foods Soil – Trace mineral content varies with the content of soil from which the food originates Processed Foods – Within all food groups, processed foods are high in sodium and chloride Drinking water – Drinking water contains varying amounts of calcium, magnesium, and other minerals; sodium is added to soften water. – Fluoride may be a natural or added component of drinking water

Roles in the body Structure to body tissues Fluid balance Acid-base balance Nerve cell transmission Muscle contraction Vitamin, enzyme, and hormonal activities

Dietary recommendations and management of some major minerals

Sodium (Na + ) Adult AI: 19–50 yr: 1.5 g 50–70 yr: 1.3 g 71 + yr: 1.2 g Adult UL: 2.3 g 1 tsp salt = 2400 mg Na 75% of Na intake is from processed foods Functions: 1.Fluid and Electrolyte balance 2.Acid-base balance 3.Maintains muscle irritability 4.Regulates cell membrane permeability 5.Nerve impulse transmission Deficiency Rare except with chronic diarrhea or vomiting and renal disorders; nausea, dizziness, muscle cramps, apathy Toxicity Hypertension, edema

Sodium (Na + ) Food labeling (servings) Sodium free <5 mg Very low sodium <35 mg Low sodium <140 mg

Potassium (K + ) Adult AI: 4.7 g No UL Sources: Fruits and vegetables Dried peas and beans Whole grains Milk Meats Functions: 1.Fluid and electrolyte balance 2.Acid-base balance 3.Nerve impulse transmission 4.Catalyst for many metabolic reactions 5.Involved in skeletal 6.Cardiac muscle activity Deficiency Muscular weakness, paralysis, anorexia, confusion (occurs with dehydration) Toxicity (from supplements/drugs) Muscular weakness, vomiting

Calcium (Ca) Adult AI 19 – 50 yr: 1000 mg 51 + yr: 1200 mg Adult UL: 2.5 g/d SOURCES : Milk and milk products, fortified orange juice, green leafy vegetables, small fish with bones, dried peas and beans FUNCTIONS 1.Bone and teeth formation and maintenance 2.Blood clotting 3.Nerve transmission 4.Muscle contraction and relaxation, Cell membrane permeability 5.Blood pressure Deficiency Children: impaired growth Adults: osteoporosis Toxicity Constipation, increased risk of renal stone formation, impaired absorption of iron and other minerals

References Dudek, S.G (2006). Nutrition essential for Nursing Practice. 5 th edition, Lippincott, Philadelphia, USA. Whitney, W & Rolfes, SR (2008) Understanding Nutrition (11 th ed), Thomson Higher Education, Belmont, CA, USA.