B vitamins and the brain

The VITACOG trial, a preliminary clinical trial in subjects with high plasma homocysteine levels, showed that the brains of those who received B-vitamins shrank significantly less rapidly than those of the placebo group, particularly in areas that are associated with early pathological changes in Alzheimer’s.

 http://theconversation.com/how-a-simple-vitamin-b-prescription-could-help-people-with-alzheimers-37809

Author believes there were flaws in the analysis. 

What happens if I don’t get enough vitamin B12? (from NIH fact page)

Vitamin B12 deficiency causes tiredness, weakness, constipation, loss of appetite, weight loss, and megaloblastic anemia. Nerve problems, such as numbness and tingling in the hands and feet, can also occur. Other symptoms of vitamin B12 deficiency include problems with balance, depression, confusion, dementia, poor memory, and soreness of the mouth or tongue. Vitamin B12 deficiency can damage the nervous system even in people who don’t have anemia, so it is important to treat a deficiency as soon as possible.
In infants, signs of a vitamin B12 deficiency include failure to thrive, problems with movement, delays in reaching the typical developmental milestones, and megaloblastic anemia.

Large amounts of folic acid can hide a vitamin B12 deficiency by correcting megaloblastic anemia, a hallmark of vitamin B12 deficiency. But folic acid does not correct the progressive damage to the nervous system that vitamin B12 deficiency also causes. For this reason, healthy adults should not get more than 1,000 mcg of folic acid a day.

What are some effects of vitamin B12 on health?

Scientists are studying vitamin B12 to understand how it affects health. Here are several examples of what this research has shown:

Heart disease

Vitamin B12 supplements (along with folic acid and vitamin B6) do not reduce the risk of getting heart disease. Scientists had thought that these vitamins might be helpful because they reduce blood levels of homocysteine, a compound linked to an increased risk of having a heart attack or stroke.

Dementia

As they get older, some people develop dementia. These people often have high levels of homocysteine in the blood. Vitamin B12 (with folic acid and vitamin B6) can lower homocysteine levels, but scientists don’t know yet whether these vitamins actually help prevent or treat dementia.

Energy and athletic performance

Advertisements often promote vitamin B12 supplements as a way to increase energy or endurance. Except in people with a vitamin B12 deficiency, no evidence shows that vitamin B12 supplements increase energy or improve athletic performance.

What are some effects of vitamin B6 on health? (from NIH fact page)

Scientists are studying vitamin B6 to understand how it affects health. Here are some examples of what this research has shown.

Heart disease

Some scientists had thought that certain B vitamins (such as folic acid, vitamin B12, and vitamin B6) might reduce heart disease risk by lowering levels of homocysteine, an amino acid in the blood. Although vitamin B supplements do lower blood homocysteine, research shows that they do not actually reduce the risk or severity of heart disease or stroke.

Cancer

People with low levels of vitamin B6 in the blood might have a higher risk of certain kinds of cancer, such as colorectal cancer. But studies to date have not shown that vitamin B6 supplements can help prevent cancer or lower the chances of dying from this disease.

Cognitive Function

Some research indicates that elderly people who have higher blood levels of vitamin B6 have better memory. However, taking vitamin B6 supplements (alone or combined with vitamin B12 and/or folic acid) does not seem to improve cognitive function or mood in healthy people or in people with dementia.

Premenstrual Syndrome

Scientists aren’t yet certain about the potential benefits of taking vitamin B6 for premenstrual syndrome (PMS). But some studies show that vitamin B6 supplements could reduce PMS symptoms, including moodiness, irritability, forgetfulness, bloating, and anxiety.

Nausea and Vomiting in Pregnancy

At least half of all women experience nausea, vomiting, or both in the first few months of pregnancy. Based on the results of several studies, the American Congress of Obstetricians and Gynecologists (ACOG) recommends taking vitamin B6 supplements under a doctor’s care for nausea and vomiting during pregnancy.

Can vitamin B6 be harmful?

Not from food, but taking high levels of vitamin B6 from supplements for a year or longer can cause severe nerve damage which goes away when you discontinue.

What are some effects of folate on health? (from NIH fact page)

Scientists are studying folate to understand how it affects health. Here are several examples of what this research has shown.

Neural tube defects

Taking folic acid regularly before becoming pregnant and during early pregnancy helps prevent neural tube defects in babies. But about half of all pregnancies are unplanned. Therefore, all women and teen girls who could become pregnant should consume 400 mcg of folic acid daily from supplements, fortified foods, or both in addition to the folate they get naturally from foods.

Since 1998, the U.S. Food and Drug Administration has required food companies to add folic acid to enriched bread, cereal, flour, cornmeal, pasta, rice, and other grain products sold in the United States. Because most people in the United States eat these foods on a regular basis, folic acid intakes have increased and the number of babies born with neural tube defects has decreased since 1998.

Preterm birth, congenital heart defects, and other birth defects

Taking folic acid might reduce the risk of having a premature baby and prevent birth defects, such as congenital heart problems. But more research is needed to understand how folic acid affects the risk of these conditions.

Cancer

Folate that is found naturally in food may decrease the risk of several forms of cancer. But folate might have different effects depending on how much is taken and when. Modest amounts of folic acid taken before cancer develops might decrease cancer risk, but high doses taken after cancer (especially colorectal cancer) begins might speed up its progression. For this reason, high doses of folic acid supplements (more than the upper limit of 1,000 mcg) should be taken with caution, especially by people who have a history of colorectal adenomas (which sometimes turn into cancer). More research is needed to understand the roles of dietary folate and folic acid supplements in cancer risk.

Heart disease and stroke

Some scientists used to think that folic acid and other B-vitamins might reduce heart disease risk by lowering levels of homocysteine, an amino acid in the blood. But although folic acid supplements do lower blood homocysteine levels, they don’t decrease the risk of heart disease. Some studies have shown that a combination of folic acid with other B-vitamins, however, helps prevent stroke.

Dementia, cognitive function, and Alzheimer’s disease

Folic acid supplements with or without other B-vitamins do not seem to improve cognitive function, but more research on this topic is needed.

Depression

People with low blood levels of folate might be more likely to suffer from depression and might not respond as well to treatment with antidepressants as people with normal folate levels.

Folic acid supplements might make antidepressant medications more effective. But it is not clear whether these supplements help people with both normal folate levels and those with folate deficiency. More research is needed to learn about the role of folate in depression and whether folic acid supplements are helpful when used in combination with standard treatment.

Can folate be harmful?

Folate that is naturally present in food is not harmful. Folic acid in supplements and fortified foods, however, should not be consumed in amounts above the upper limit, unless recommended by a health care provider.