Water and Nutrition Health Article

Nutrition for optimal health

Not only is water necessary to sustain life, but proper nutrition is also required to ensure optimal health. Consumption of wide variety of foods, with adequate vitamin and mineral intake is the basis of a healthy diet. Vitamins are compounds that are essential in small amounts for proper body function and growth. Vitamins are either fat soluble: A, D, E, and K; or water soluble: vitamin B and C. The B vitamins include vitamins B₁ (thiamine), B₂ (riboflavin), and B₆ (pyridoxine), pantothenic acid, niacin, biotin, folic acid (folate), and vitamin B₁₂ (cobalamin).

Researchers state that no single nutrient is the key to good health, but that optimum nutrition is derived from eating a diverse diet including a variety of fruits and vegetables. Because there are many more nutrients available in foods such as fruits and vegetables than vitamin supplements, food is the best source for acquiring needed vitamins and minerals. The mineral nutrients are defined as all the inorganic elements or inorganic molecules that are required for life. As far as human nutrition is concerned, the inorganic nutrients include water, sodium, potassium, chloride, calcium, phosphate, sulfate, magnesium, iron, copper, zinc, manganese, iodine, selenium, and molybdenum. Other inorganic nutrients include phosphate, sulfate, and selenium. Inorganic nutrients have a great variety of functions in the body. The electrolytes are affected by fluid balance in particular (sodium, potassium, calcium, phosphate, and magnesium etc.). Water, sodium, and potassium deficiencies are most closely associated with abnormal nerve action and cardiac arrhythmias.

Laboratory studies with animals have revealed that severe deficiencies in any one of the inorganic nutrients can result in very specific symptoms, and finally in death, due to the failure of functions associated with that nutrient. In humans, deficiency in one nutrient may occur less often than deficiency in several nutrients. A patient suffering from malnutrition is deficient in a variety of nutrients.

Complications

Sodium deficiency (hyponatremia) and water imbalances (dehydration) are the most serious and widespread deficiencies in the world. These electrolyte deficiencies tend to arise from excessive losses from the body, such as during prolonged and severe diarrhea or vomiting. Diarrheal diseases are a major world health problem, and are responsible for about a quarter of the 10 million infant deaths that occur each year. Nearly all of these deaths occur in impoverished parts of Africa and Asia, where they result from contamination of the water supply by animal and human feces.

Dehydration is a deficit of body water that results when the output of water exceeds intake. Dehydration stimulates the thirst mechanism, instigating water consumption. Sweating and the output of urine both decrease. If water intake continues to fall short of water loss, dehydration worsens.

Causes of dehydration may include:

• vomiting
• diarrhea
• diuretics
• excessive heat
• excessive sweating
• fever
• decreased water intake

Dehydration induces water to move from the reservoir inside cells into the blood. If dehydration progresses, body tissues begin to dry out and the cells start to shrivel and malfunction. The most susceptible cells to dehydration are the brain cells. Mental confusion, one of the most common signs of severe dehydration may result, possibly leading to coma. Dehydration can occur when excessive water is lost with diseases such as diabetes mellitus, diabetes insipidus, and Addison's disease.

Dehydration is often accompanied by a deficiency of electrolytes, sodium and potassium in particular. Water does not move as rapidly from the reservoir inside of the cells into the blood when electrolyte concentration is decreased. Blood pressure can decline due to a lower volume of water circulating in the bloodstream. A drop in blood pressure can cause light-headedness, or a feeling of impending blackout, especially upon standing (orthostatic hypotension). Continued fluid and electrolyte imbalance may further reduce blood pressure, causing shock and damage to many internal organs including the brain, kidneys, and liver.

Consumption of plain water is usually sufficient for mild dehydration. However, when both water and electrolyte losses have occurred after vigorous exercise, electrolytes must be replaced, sodium and potassium in particular. Adding a little salt to drinking water or consuming drinks such as Gatorade during or following exercise can replace lost fluids. Individuals with heart or kidneys problems should consult a physician regarding the replacement of fluids after exercise.

Overhydration is an excess of body water that results when water intake exceeds output. Drinking large amounts of water does not typically lead to overhydration if the kidneys, heart, and pituitary gland are functioning properly. An adult would have to drink more than7.6 L per day (2 US gallons/day) to exceed the body's ability to excrete water. Excessive body water causes electrolytes in the blood, including sodium to become overly diluted. Overhydration occurs in individuals whose kidneys do not function normally, primarily in kidney, heart, or liver disease. People with these conditions may have to limit their water and dietary salt intake. Similar to dehydration, the brain is the most sensitive organ to overhydration. The brain cells can adapt to increased fluid volume when overhydration increases slowly, however, when it occurs rapidly, mental confusion, seizures, and coma can result.