Vitamin B-12 is known as the energy vitamin. When people suffer from chronic fatigue, they often are given vitamin B-12 injections to boost their energy. We get some vitamin B-12 from foods, such as leafy green vegetables, eggs and fish. But the ability to absorb vitamin B-12 from food diminishes as we age. And common drugs, such as some antibiotics, birth-control pills and GERD medications, can cause vitamin B-12 deficiency. You can work with a doctor to determine if you need to supplement with B vitamins. It might just be the energy boost you need!