What's the Difference Between B-12 and B Complex Vitamins?

B Complex vs. B-12
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Vitamins are micronutrients, meaning that your body only requires them in minute quantities. They don't directly provide energy, yet they're critical for life. According to the University of Maryland Medical Center, a vitamin-rich diet can help you stave off many diseases. B-complex vitamins are water soluble and, by definition, the body doesn't store them. B-12 is the B vitamin your body requires in the least amount, yet it's as essential as its counterparts.

B-Complex Contents

B complex is actually a group of eight distinct vitamins. Besides B-12, the group includes thiamine, also known as B-1; riboflavin, or B-2; niacin, or B-3; pantothenic acid, also called B-5; pyridoxine, or B6; biotin, or B-7; and folic acid. Alternate names for folic acid are folate, or B-9, while niacin also goes by nicotinamide, or nicotinic acid amide. B-12 is an exception among B vitamins in that your liver stores as much as 90 percent of your body's content. According to registered dietitians Liz da Silva and Stacey McCray, your body can store up to five years' worth of B-12 supply, depending on your diet and health status.

B-12 Functions

Also known as cobalamin, vitamin B-12 is a compound that contains the mineral cobalt. Like several other B vitamins, B-12 is important for normal growth and development because of its involvement in nutrient metabolism. It specifically helps your body derive energy from carbs, fats and proteins, according to the Massachusetts Institute of Technology. It also works with folic acid to help your body produce your genetic material, red blood cells and the lining on your nerve cells..

Functions of Other B Vitamins

B-complex vitamins play critical roles in your body, especially in the metabolism of macronutrients, which includes carbohydrates, protein and fat. Vitamins B-1, B-2, B-3, B-5 and biotin specifically help convert carbs from foods into energy. B-3 and B-5 also play an important role in the metabolism of proteins and fats. Additionally, several B vitamins are essential for normal heart, muscle and nerve function. If you're pregnant, folic acid is critical to prevent birth defects, such as spina bifida, in the developing fetus, while choline helps with a baby's brain development, learning and memory.

Dietary Sources

Supplements can provide you with a combination of B vitamins and other nutrients. But according to the University of Maryland Medical Center, you don't need supplementation if you're healthy and have a normal, balanced diet. Nearly all foods contain B-5, and many products containing white flour or other refined grains are routinely enriched with B-1, B-2 and B-3. Nuts, legumes, citrus fruits, green vegetables, dairy products and meats — especially organ meats — are generally good sources of B vitamins. If you're a strict vegetarian, however, you're at greater risk for B-12 deficiency, because this vitamin naturally occurs in animal products only. Adding foods fortified with the essential B vitamin can help ensure you get what you need.