Nutrients are the substances an organism requires for survival. When an organism is denied the nutrients it needs, the health of that organism will suffer. Essential nutrients are the nutrients that an organism cannot synthesize on its own or cannot produce in sufficient quantities. An organism must obtain these essential nutrients from outside sources. If an organism is deprived of its essential nutrients it cannot function properly and will ultimately die.
The specific essential nutrients vary from organism to organism. The human body requires six types of essential nutrients to maintain its health: water, proteins, carbohydrates, fats, vitamins, and minerals. A lack of any one of these will cause a person to become ill due to malnutrition, and a severe deficiency can result in death. Because of this, it is important to have an understanding of the sources of essential nutrients to maintain good health.
Background
In developed nations, adequate levels of essential nutrients can be easily acquired through diet throughout the year. Potable water and reasonably priced sources of the macronutrients—proteins, fats, and carbohydrates—are readily available.
Fats in the form of oil, butter, and foods such as avocado, fish, and nuts are typically close at hand. Fats include the essential fatty acids: alpha-linolenic acid, an omega-3 fatty acid that can be found in soy, rapeseed, and flax; and linolenic acid, an omega-6 fatty acid that can be found in a variety of vegetable oils. Fats are a significant source of energy and can increase the body’s absorption of fat-soluble vitamins.
Proteins are made of chains of amino acids and can be found in relatively inexpensive and readily available foods such as eggs, nuts, meats, and soy protein. Of the twenty-one amino acids that make up proteins, nine are essential in human nutrition and cannot be synthesized. Proteins are a vital component of all cells.
Carbohydrates, the third class of macronutrients, are a vital source of energy for the human body. Complex carbohydrates can be obtained from foods such as cereals, breads, and pasta, while simple carbohydrates include a variety of sugars.
The essential micronutrients include vitamins and minerals. The thirteen essential vitamins are vitamin A, the eight B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, vitamin B-12, and folate), vitamin C, vitamin D, vitamin E, and vitamin K. Vitamins perform a variety of essential functions in the body and can be found in dark-colored fruits, dark leafy vegetables, egg yolks, fortified dairy products, whole grains, lentils, beans, fish, liver, and beef. Eating a varied diet is the best way to ensure one receives all of the essential vitamins.
Minerals that are essential to human nutrition include sodium, potassium, calcium, magnesium, and iodine. Adequate levels of sodium and potassium help to maintain cell function and balance fluid volumes, while calcium is critical to bone health.
Where there are adequate supplies of foods containing essential nutrients, a number of diseases that can be attributed to nutritional deficiencies can be prevented with little or no effort. All that is required is to eat a wide variety of foods or foods that are rich in the associated nutrients. Enriched foods and daily vitamins provide many essential nutrients. Many breakfast cereals and breads, as well as milk and salt, are enriched or fortified. It is important to check food labels to see what these foods have in the way of essential nutrients and to seek sources for what is not included.
Impact
In some parts of the world, many people do not have access to the foods they require for a sufficient quantity of essential nutrients. When this is the case, people will be undernourished, which leads to various health problems and reduced resistance to illnesses. Children who do not receive adequate nutrition will not reach their full potential in terms of physical or cognitive development. Adults who do not receive adequate nutrition are unlikely to have long life expectancies. Infant mortality rates will also be high, due to low birth weights and the effects of nutritional deficiencies; for example, folic acid deficiency is the principal cause of neural tube defects , a potentially fatal birth defect.
There are many conditions and diseases that result from a lack of essential nutrients. While these are nearly unheard of in developed nations, they are serious ailments in developing nations. Some of the more well-known are rickets, beriberi, pellagra, scurvy, anemia, and goiter. Rickets results from a lack of vitamin D and causes bowed legs, weak bones, and dental deformities. Beriberi is due to insufficient thiamin intake and causes atypical muscle coordination and damage to the nerves, resulting in loss of feeling in the extremities and confusion. Pellagra results from insufficient niacin and causes dementia. Scurvy is the result of a lack of vitamin C and causes internal bleeding and severe problems with the teeth and gums. Insufficient quantities of iron, vitamin B6, or vitamin B12 result in anemia, which leads to extreme fatigue and weakness. Goiter can arise from insufficient iodine; however, goiter due to iodine deficiency is rare in developed countries due to the use of iodized salt. Symptoms of this disease include an enlarged thyroid gland and difficulties breathing. Each of these diseases can be prevented or reversed by adequate intake of essential nutrients.
The principal cause of nutritional deficiencies worldwide is poverty and limited access to a varied and healthy diet; however, fad diets, drug interactions, alcoholism, genetic abnormalities, or gastrointestinal problems can also lead to inadequate levels of essential nutrients in the body. Whatever the cause of nutritional deficiencies, they take a significant toll on those affected, as well as their countries and communities. The human body cannot synthesize these nutrients; without access to sources of these nutrients, it is not possible for people to maintain good health.
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