B-complex vitamins are nutrients that help your body convert calories into energy. They are also important for vision, normal appetite, and healthy skin, hair and nails. In addition, they play a role in the formation of red blood cells and the functioning of the nervous system. Vitamin B100 complex supplements contain most of the B vitamins in doses of 100 milligrams, except for a few B vitamins that you need in much smaller doses. The 100-milligram dosage is much higher than the recommended daily value. However, because B vitamins are not stored in the body's fat tissues the way some vitamins are, B-vitamin toxicity is not generally an issue.
Increase Energy and Improve Mood
Because B-complex vitamins help convert the food you eat into usable energy, they may also be effective in increasing energy levels. A study published in "Psychopharmacology" in 2010 found that there was significant improvement in the mental health of male participants after 33 days of supplementation with a B-complex vitamin, along with vitamin C and a mineral supplement. Subjects reported increased vigor and overall improvements in mood, as well as reductions in stress levels.
Many B-complex vitamins are sold under the name "B-stress" for their perceived ability to decrease stress levels. A study published in 2011 in "Human Psychopharmacology" tested whether a high-dose B-complex vitamin could decrease the psychological strain associated with chronic work stress. The double-blind, randomized, placebo-controlled trial was conducted over a three-month period. Researchers concluded that a B-complex vitamin could serve as a cost-effective treatment for improving mood and decreasing the mental strain brought on by occupational stress.
Healthy Hair, Skin and Nails
B-complex vitamins are important for healthy hair, skin and nails. According to the California Nutrition and Physical Activity Guidelines for Adolescents, one B vitamin, either folate or folic acid, when taken daily can help promote glowing skin, shiny hair and strong, healthy nails. Folate is required in smaller amounts than other B vitamins, with a daily recommendation of 400 micrograms. Biotin is another B vitamin that is particularly important for maintaining healthy hair, skin and nails. MedlinePlus notes that biotin is used to treat brittle nails, hair loss and skin rashes.
Insufficient vitamin-B intake can lead to a variety of diseases and conditions. MedlinePlus notes that insufficient levels of B-12 or B-6 can cause anemia. Deficiencies of biotin can lead to fatigue, loss of appetite, depression, anemia and heart abnormalities. Folate deficiencies can lead to impaired growth, anemia and diarrhea, and insufficient niacin can cause nausea, skin problems and cramps. Taking a B100 complex will ensure that your body has an abundance of each B vitamin.