Nutrition

What is meant by nutrition? The human body requires seven major types of nutrients

A nutrient is a source of nourishment, an ingredient in a food, e.g. protein, carbohydrate, fat, vitamin, mineral, fiber and water. Macronutrients are nutrients we need in relatively large quantities. Micronutrients are nutrients we need in relatively small quantities.

Energy macronutrients - these provide energy, which is measured either in kilocalories (kcal)

Carbohydrates - (4 kcal per grams):

Proteins - 4 kcal per gram

Fats - 9 kcal per grams

Other Macronutrients. These do not provide energy

. Fiber

Fiber consists mostly of carbohydrates. However because of its limited absorption by the body, not much of the sugars and starches get into the blood stream. Fiber is a crucial part of essential human nutrition.

Water

About 70% of the non-fat mass of the human body is water. Nobody is completely sure how much water the human body needs - claims vary from between one to seven liters per day to avoid dehydration.

Micronutrients Minerals

Dietary minerals are the other chemical elements our bodies need, apart from carbon, hydrogen, oxygen and nitrogen. Experts say that 16 key minerals are essential for human biochemical processes by serving structural and functional roles. Below are few important minerals.

Potassium

What it does - a systemic (affects entire body) electrolyte, essential in co-regulating ATP (an important carrier of energy in cells in the body, also key in making RNA) with sodium. Deficiency - hypokalemia (can profoundly affect the nervous system and heart). Excess - hyperkalemia (can also profoundly affect the nervous system and heart).

Chloride

What it does - a systemic (affects entire body) electrolyte, essential in co-regulating ATP (an important carrier of energy in cells in the body, also key in making RNA) with sodium. Deficiency - hypokalemia (can profoundly affect the nervous system and heart). Excess - hyperkalemia (can also profoundly affect the nervous system and heart).

Sodium

What it does - key for hydrochloric acid production in the stomach, also important for cellular pump functions. Deficiency - hypochleremia (low salt levels, which if severe can be very dangerous for health). Excess - hyperchloremia (usually no symptoms, linked to excessive fluid loss).

Calcium

What it does - important for muscle, heart and digestive health. Builds bone, assists in the synthesis and function of blood cells. Deficiency - hypocalcaemia (muscle cramps, abdominal cramps, spasms, and hyperactive deep tendon reflexes). Excess - hypercalcaemia (muscle weakness, constipation, undermined conduction of electrical impulses in the heart, calcium stones in urinary tract, impaired kidney function, and impaired absorption of iron leading to iron deficiency).

Phosphorus What it does - component of bones and energy processing. Magnesium

What it does - required for good bones.

Zinc

What it does - required by several enzymes.

Iron

What it does - required for proteins and enzymes, especially hemoglobin. Deficiency - anemia. Excess - iron overload disorder; iron deposits can form in organs, particularly the heart.

Manganese

What it does - a cofactor in enzyme functions. Deficiency - wobbliness, fainting, hearing loss, weak tendons and ligaments. Less commonly, can be cause of diabetes. Excess - interferes with the absorption of dietary iron.

Iodine

What it does - required for the biosynthesis of thyroxine (a form of thyroid hormone).

Vitamins

Vitamins are classified as water soluble (they can dissolve in water) or fat soluble (they can dissolve in fat). For humans there are 4 fat-soluble (A, D, E, and K) and 9 water-soluble (8 B vitamins and vitamin C) vitamins - a total of 13.

Water soluble vitamins need to be consumed more regularly because they are eliminated faster and are not readily stored. Urinary output is a good predictor of water soluble vitamin consumption. Several water-soluble vitamins are manufactured by bacteria.

Fat soluble vitamins are absorbed through the intestines with the help of fats (lipids). They are more likely to accumulate in the body because they are harder to eliminate quickly. Excess levels of fat soluble vitamins are more likely than with water-soluble vitamins - this condition is called hypervitaminosis

Vitamin A

• chemical names - retinol, retinoids and carotenoids.
• Solubility - fat.
• Deficiency disease - Night-blindness.
• Overdose disease - Keratomalacia (degeneration of the cornea).

Vitamin B1

• chemical name - thiamine.
• Solubility - water.
• Deficiency disease - beriberi, Wernicke-Korsakoff syndrome.
• Overdose disease - rare hypersensitive reactions resembling anaphylactic shock when overdose is due to injection. Drowsiness.

Vitamin B2

• chemical name - riboflavin
• Solubility - water
• Deficiency disease - ariboflanisosis (mouth lesions, seborrhea, and vascularization of the cornea).
• Overdose disease - no known complications. Excess is excreted in urine.

Vitamin B3

• chemical name - niacin.
• Solubility - water.
• Deficiency disease - pellagra.
• Overdose disease - liver damage, skin problems, and gastrointestinal complaints, plus other problems.

Vitamin B5

• chemical name -pantothenic acid.
• Solubility - water.
• Deficiency disease - paresthesia (tingling, pricking, or numbness of the skin with no apparent long-term physical effect).
• Overdose disease - none reported.

Vitamin B6

• chemical name - pyridoxamine, pyridoxal.
• Solubility - water.
• Deficiency disease - anemia, peripheral neuropathy.
• Overdose disease - nerve damage, proprioception is impaired (ability to sense stimuli within your own body is undermined).

Vitamin B7

• chemical name - biotin.
• Solubility - water.
• Deficiency disease - dermatitis, enteritis.
• Overdose disease - none reported.

Vitamin B9

• chemical name - folinic acid.
• Solubility - water.
• Deficiency disease - birth defects during pregnancy, such as neural tube.
• Overdose disease - seizure threshold possibly diminished.

Vitamin B12

• chemical name - cyanocobalamin, hydroxycobalamin, methylcobalamin.
• Solubility - water.
• Deficiency disease - megaloblastic anemia (red blood cells without nucleus).
• Overdose disease - none reported.

Vitamin C

• chemical name - ascorbic acid.
• Solubility - water.
• Deficiency disease - scurvy, which can lead to a large number of complications.
• Overdose disease - vitamin C megadosage - diarrhea, nausea, skin irritation, burning upon urination, depletion of the mineral copper, and higher risk of kidney stones.

Vitamin D

• chemical name - ergocalciferol, cholecalciferol.
• Solubility - fat.
• Deficiency disease - rickets, osteomalacia (softening of bone), recent studies indicate higher risk of some cancers.
• Overdose disease - hypervitaminosis D (headache, weakness, disturbed digestion, increased blood pressure, and tissue calcification).

Vitamin E

• chemical name - tocotrienols.
• Solubility - fat.
• Deficiency disease - very rare, may include hemolytic anemia in newborn babies.
• Overdose disease - one study reported higher risk of congestive heart failure.

Vitamin K

• chemical name - phylloquinone, menaquinones.
• Solubility - fat.
• Deficiency disease - greater tendency to bleed.
• Overdose disease - may undermine effects of warfarin