Water and Minerals: Essential Nutrients for Human Health

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Water is a vital component of the human body, comprising 45-75% of an average adult's body weight. The percentage varies based on several factors:

Body Composition: Muscle tissue contains about 75% water, while fat tissue contains only 1-20% water.
Age: Elderly individuals have less body water due to decreased muscle mass.
Gender: Males typically have a higher percentage of body water than females because they have more muscle and less fat.

Universal Solvent: Dissolves and transports nutrients and waste products.
Maintains Body Temperature: Regulates heat through sweating and respiration.
Lubricant: Cushions joints and tissues.
Cushion for Cells: Protects organs and tissues from shock.

Extracellular Fluid: Located outside cells, including blood plasma. Regulated mainly by sodium (Na) and chloride (Cl).
Intracellular Fluid: Located inside cells. Regulated mainly by potassium (K) and phosphate (P).
Most body water is found inside cells (intracellular).

Inorganic: Do not contain carbon; not destroyed by heat or light.
Food Content: Amount in food depends on soil composition.
Functions: Essential for bone and teeth structure, fluid balance, and as cofactors for enzyme activity.
Absorption: Minerals can compete with each other for absorption in the digestive tract.

Distribution: 99% in bones and teeth; 1% in blood and soft tissues.
Association: Phosphorus is commonly found with calcium in bones and teeth.
Most Abundant Mineral: Calcium is the most abundant mineral in the body.
Absorption: Enhanced by vitamin D, lactose, and phosphorus.
Functions:
- Provides skeletal strength
- Maintains fluid and electrolyte balance for nerve transmission
- Muscle contraction and prevention of spasms
- Acts as a cofactor in enzyme systems
Bone Mass Density: Peaks at ages 20-30; bone loss accelerates in women after menopause.

Diagnosis: DXA (dual-energy x-ray absorptiometry) scan.
Risk Factors: Inadequate calcium and vitamin D intake, genetics, lack of weight-bearing exercise, smoking, excessive alcohol use, eating disorders.

Calcium Carbonate: Most common supplement form; maximum absorption per dose is 500 mg.
Calcium-Fortified Orange Juice: Must be shaken well before pouring to ensure even distribution.

Dairy: 1 cup of milk or yogurt provides about 300 mg of calcium; bioavailability is 20-30%.
Vegetables: Kale has higher bioavailability (40%) than spinach, which is low due to oxalates and phytates that bind calcium.

Location: Most magnesium is stored in bones and teeth.
Function: Essential for healthy bone metabolism.
Food Sources: Dark green, leafy vegetables.
Supplements: Many adults do not meet recommended intake; doses over 350 mg/day may cause diarrhea.

Location: Primarily found outside cells (extracellular fluid).
Function: Maintains water balance in the body.
Chloride: Usually found with sodium as sodium chloride (NaCl, table salt).
Toxicity: Excess sodium can cause hypertension (high blood pressure) in some individuals.
DASH Diet: Dietary Approach to Stop Hypertension; emphasizes low sodium, high potassium, reduced processed foods, and increased fruit intake.
Other Factors: Weight loss and genetics can influence blood pressure.
Deficiency: Can cause muscle cramps.

Most Abundant Trace Mineral: Most iron is found in hemoglobin of red blood cells.
Function: Transports oxygen to all cells.
Absorption:
- Heme iron (from red meat) is better absorbed than non-heme iron (from plants).
- Absorption increases with greater need for iron and adequate stomach acid (HCl).

Most Common Deficiency Worldwide
Symptoms: Fatigue, increased infections, headaches, pale skin, intolerance to cold.
High-Risk Groups: Pregnant women, women of child-bearing age, vegans, children, individuals with blood loss.
RDA: Women: 18 mg/day; Men: 8 mg/day.

Best Bioavailability: Red meat (heme iron), e.g., hamburger.
Other Sources: Egg yolk, dark green vegetables, peas, legumes, molasses, dark chicken meat.
Cooking Tip: Simmering tomato sauces in an iron skillet increases iron content.

Mineral	Functions	Sources	Deficiency	Toxicity
Zinc	DNA & RNA synthesis, immune system function	Oysters, red meat, whole grains (less in fruits & vegetables)	Impaired immunity, delayed wound healing (Additional info: not specified in original notes)	Can cause nausea, vomiting, immune suppression (Additional info: not specified in original notes)
Selenium	Antioxidant	Brazil nuts, seafood, grains (depends on soil concentration)	Possible heart damage	Brittle nails & hair
Fluoride	Prevents tooth decay, strengthens bones	Fluoridated water	Tooth cavities	Joint stiffness, osteoporosis

Some deficiency and toxicity symptoms for zinc were inferred based on standard nutrition knowledge.