Nutrition refers to the balance of nutrients taken into the body versus the bodies requirements for them. These nutrients break down into various categories and classifications. Ways of classifying nutrients include assessing:

	Solids -v- Liquids
	Macro-nutrients -v- Micronutrients
	Fats -v- Carbohydrates -v- Proteins
	Fibre (Wet -v- Dry) Content
	Caloric content (calories or kilojoules)

It is important to understand that nutrition and nutritional requirements represent an ever-changing picture, a balance between requirements and input (food and supplements). Factors which influence this balance include:

	Intake
	Absorption
	Utilisation
	Storage
	Excretion

A Deficiency State occurs when the body's requirements are not met, and this naturally varies from individual to individual. This can result from alteration to the factors listed above, ie

	Decreased Intake: not eating, starvation and dieting, poor food choices, problems with chewing or swallowing
	Decreased Absorption: gastrointestinal illness, alcohol, drugs
	Decreased Storage: metabolic disease, liver disease
	Increased utilisation: growing, pregnancy, lactation, surgery, infection, trauma, drugs (including the Pill)
	Increased Excretion: gastrointestinal disease, drugs

Some people are particularly vulnerable to nutritional deficiency for one or more of the reasons mentioned above.

Increased Nutritional Risk:

	Chronic Illness
	Hospitalised
	Institutionalised
	Drug abuse
	Alcohol abuse
	Long term medication
	Recent immigrants
	Aborigines
	Homeless
	Solitary living
	Teenagers
	Elderly
	Pregnant/lactating women