What Are The Two Most Important Nutrients For A Healthy Body?

Nutrients serve a variety of important functions and most share a common characteristic: they are essential for life. Choosing the most important nutrients is like choosing between air and water--humans need them both. If it is a question of what nutrient is most essential to life and health, a nutrient that serves as a calorie source is a good pick, as that would keep you from starving. However, without vitamins and minerals, life may be possible, but it would surely be unbearable, as deficiencies of these micronutrients produce symptoms ranging from sore gums to diarrhea and dementia. Therefore, what matters most is to ensure your diet meets your caloric needs while providing daily requirements for vitamins and minerals.

Macronutrients

The macronutrients are dietary calorie sources. The three major macronutrients are carbohydrates, protein and fat. If you imbibe, alcohol represents a fourth source of calories, providing 7 calories per gram. Of the macronutrients, only protein is required for life. Dietary protein provides essential amino acids that your body cannot synthesize. These amino acids are used to build cellular components and muscles, for example. Carbohydrates and fats are major sources of calories in a healthy diet. They are broken down to glucose, which provides energy to your cells. Protein can also be broken down to form glucose.

Macronutrient Ratio

A healthy diet provides all three macronutrients, in a ratio of roughly 55 percent carbohydrate, 30 percent fat and 15 percent protein, according to the Institutes of Medicine. Deficiencies or excesses in one or another of these major calorie forms can pose health risks. For example, a diet lacking protein can lead to muscle wasting. A diet with excessive fat intake, especially in the form of saturated fat or cholesterol, can increase your risk for heart disease and some forms of cancer. Because carbohydrates are your body's primary energy source, deficiencies can leave you feeling sluggish, while eating too many simple sugars, such as sodas and candies, is associated with diseases such as obesity and diabetes.

Vitamins

All 13 essential vitamins are required for the proper function of your body. Vitamins are calorie-free and therefore not energy sources, which means you could go on living, at least for a time, without thembut would suffer a long list of vitamin deficiency-related diseases. Vitamin A deficiency leads to blindness. Thiamine deficiency leads to memory loss. Vitamin B-12 deficiency can cause numbness and tingling in your legs, and vitamin K deficiency, though uncommon, can give rise to a tendency to bleed. Eat a varied diet to ensure adequate intake of vitamins, and take a multi-vitamin, according to Harvard School of Public Health.

Minerals

Like vitamins, minerals are essential nutrients that do not provide calories. They participate in essential chemical reactions that make life without them possible but unpleasant. Some of the major minerals required in your diet include calcium, zinc, iron and potassium. Selenium deserves special mention, as it the only mineral that functions as an antioxidant, scavenging free radicals and protecting your body from wear and tear. Brazil nuts are an excellent source. Sodium is also an essential mineral, but that doesn't mean you should go salting your next meal. Most foods, including fruits and vegetables, are naturally rich in sodium and easily meet your daily needs. So unless you are an endurance athlete or someone who sweats excessively, you may do best holding the salt.

Fiber

A healthy body is built from a healthy diet, and in addition to calories, vitamins and minerals, your body depends on fiber to operate optimally. Consider that the length of your digestive tract is roughly 30 feet. Without the bulk provided by fiber, your body has a hard time moving food over such a long distance, and the result can be constipation and its consequences, including hemorrhoids and rectal fissures. The Institute of Medicine recommends 25 g of fiber for adult females, and 38 g per day for adult males -- to assure you get the most of your nutrition.