High doses of B vitamins aren’t likely to preserve your memory or thinking ability.
Researchers examined 11 large controlled trials that gave a total of 22,000 (mostly older) people either a placebo or (typically) high doses of folic acid (400 to 2,500 mcg a day), usually along with vitamins B-6 (3 to 50 mg) and B-12 (20 to 1,000 mcg). After 4 months to 7 years, the B-vitamin takers scored no better on cognitive tests than placebo takers.
What to do: High doses of B vitamins won’t keep your brain from aging. However, if you’re over 50, get the Recommended Dietary Allowance (2.4 mcg a day) of B-12 from a fortified food (like cereal) or a supplement.
Source: Am. J. Clin. Nutr. 100: 657,2014.
Other relevant links:
- Don’t rely on antioxidant and B vitamin supplements to keep your memory intact. See: Antioxidant and B vitamin supplements for your brain
- Digestive systems change as we age, increasing the need for vitamin B-12. See: Vitamin Supplements: The Need for B-12 as We Get Older
- B vitamin supplements may decrease risk of macular degeneration. See: Is There a Benefit from B Vitamin Supplements?