Nutrient Spotlight: Benefits of B Vitamins

B vitamins are vital multitaskers. They are involved in everything from cognitive function and mood to energy production and heart health. Multivitamins contain a smattering of B vitamins, so what else do you need to know? 

Actually, there’s a lot of research, especially on folic acid, vitamin B12, and vitamin B6.

B Vitamins Give You 7 Powerful Benefits

B vitamins help you to...

1. Stay mentally sharp. We lose about two percent of our brain volume every decade as we get older. Although this is a normal part of aging, accelerated atrophy is linked with Alzheimer’s disease and dementia. Folic acid and vitamins B6 and B12 reduce levels of homocysteine, a toxic amino acid linked with an increased risk of Alzheimer’s disease. In one study, scientists noted marked reductions in brain atrophy in participants who had taken high doses of B vitamins for two years, as compared to those on placebo. Those whose initial homocysteine levels were highest reaped the greatest benefits—their rate of atrophy was half that of the placebo group. The vitamin takers also scored higher on tests of cognitive function.
    
2. Prevent cardiovascular disease. An elevated level of homocysteine is also a well-established risk factor for cardiovascular disease. Excess homocysteine spills out of the cells and into the bloodstream, where it damages the arteries, setting the stage for atherosclerosis (the buildup of plaque in the arteries). According to Harvard researchers, a high blood level of homocysteine more than triples the risk of heart attack. It also dramatically increases the likelihood of having a stroke and has been linked to other conditions caused by atherosclerosis, such as erectile dysfunction, retinopathy, peripheral vascular disease, and kidney disease.
    
3. Keep your bones strong. Everybody knows that calcium and vitamin D protect against osteoporosis and fractures. However, Harvard researchers discovered significant links between elevated levels of homocysteine and risk of hip fracture in postmenopausal women.
    
4. Preserve your vision. Another Harvard study revealed that these vitamins also protect the eyes. In this placebo-controlled trial, women who took daily folic acid, B6, and B12 supplements had a reduced risk of developing age-related macular degeneration. In addition, several studies have found that long-term use of B vitamins, along with vitamins A, C, and E, and carotenoids (particularly lutein and zeaxanthin), reduces risk of cataracts.
    
5. Boost your energy. Vitamin B12 is an excellent energy booster. This nutrient is a key player in the burning of fats and carbohydrates for energy, the formation of healthy red blood cells, and the maintenance of the myelin sheaths that protect nerves. Because of these diverse roles, a deficiency of vitamin B12 can cause symptoms ranging from mild fatigue to severe exhaustion.
    
6. Lift your mood. The dynamic trio of folic acid and vitamins B6 and B12 also improves mood. These nutrients play an indirect but critical role in the formation of serotonin and other neurotransmitters, and deficiencies—as well as high levels of homocysteine—are linked with mood disorders. Although B-complex vitamins are not a stand-alone treatment for depression, they’re an important adjunct.
    
7. Stave off allergies and asthma. A research team at Johns Hopkins discovered that individuals with the lowest blood levels of folate (folic acid) are at a significantly increased risk of skin and respiratory allergies, wheezing, and asthma.

How Much Should You Take?

Forget about the RDAs. As an example, the RDA of B12 for adults is just 2.4 mcg per day. Dutch researchers found that normalizing a mild B12 deficiency, however, required between 647 and 1,032 mcg, which is 300–500 times more than the RDA!

My recommended minimum daily doses for healthy people are: 800 mcg of folic acid, 150 mcg of vitamin B12, and 75 mg of vitamin B6. People with high homocysteine levels or any of the conditions mentioned above may take up to 6,000 mcg of folic acid, 2,000 mcg of vitamin B12, and 125 mg of B6. (Neurological conditions tend to respond better to the methylcobalamin form of vitamin B12.) These vitamins are safe and well tolerated. However, very high doses of B6 may cause nerve damage.