You’re probably aware that some medications can block the effects of others. But did you know that some nutrients can magnify each other? Such is the case with omega-3 fatty acids and B vitamins, as was just demonstrated in a recent meta-analysis. 
Both omega-3s and several B vitamins have been shown to help keep homocysteine, a harmful amino acid metabolite, in check.* (Elevated levels of homocysteine can negatively affect bone health, heart health, and cognitive function.) However, not all studies have been positive. Until recently prior results had been frustratingly inconsistent, begging the question: Do these nutrients lower homocysteine, or don’t they?
But now, researchers from Deakin University in Australia think they understand the reason for the discrepancy: It may be that omega-3s and certain B vitamins (specifically folic acid, vitamin B6, and vitamin B-12) work together to support healthy homocysteine levels, and that if one is missing, the positive effect is diminished.*
Their meta-analysis evaluated the results of 21 controlled trials of omega-3 supplements — taken with or without B vitamins — on homocysteine levels. They determined that 0.2 to 6 grams of omega-3s combined with B vitamins was associated with an 8.5 percent drop in homocysteine.*
These findings corroborate those of a study published last year in the American Journal of Clinical Nutrition, which found that supplementing with B vitamins could support older folks’ memory, but only if omega-3 were already at healthy levels. 
How to make sure you’re getting enough? Folic acid and vitamin B6 are found in beans, as well as many fruits and vegetables, especially dark leafy greens and citrus fruits. Animal products such as fish, poultry, meat, eggs, and dairy supply vitamin B12, which is why vegans often need a B12 supplement. Omega-3s are found in fatty fish such as salmon, as well as in walnuts and chia seeds. Many people find it convenient to take an omega-3 supplement in the form of fish or flax oil.
Wherever you get your B vitamins and omega-3s, however, one thing is becoming increasingly clear: It’s best to take them together.
* This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, cure, treat, or prevent any disease.
 Dawson SL, Bowe SJ, Crowe TC. Nutr Res. Jun;36(6):499-508
 Jerneren F, et al. Am J Clin Nutr. 2015 Jul;102(1):215-21