Should you take a vitamin B₁₂ supplement?

You may need a little or a lot of B₁₂, but it's worth investigating.

Annie Oakley, the larger-than-life sharpshooter and star of Buffalo Bill's Wild West Show, was cut down by an invisible foe: a deadly form of anemia caused by a lack of vitamin B₁₂.

Back in Annie's day, we didn't know B₁₂ existed or that deficiency could lead to dangerous consequences (for Annie, it was death in 1926). It wasn't until later in the 20th century that scientists discovered B₁₂ and how to use it as a treatment.