B12 vitamin-rich foods
Also known as the "energy vitamin," B12 is responsible for energy production. So if your body is low or isn't absorbing B12, you may feel sluggish. B12 is present in eggs, meat, fish, dairy, nori seaweed, and some varieties of mushrooms and tempeh, a fermented soy product.
Studies suggest that one in four American adults is deficient and almost two-fifths or more of the population has sub-optimum levels. Older adults are at a higher risk for B12 deficiency, as are vegans. The body requires hydrochloric acid and IF (intrinsic factor) to absorb B12, so deficiency may be due to a lack of the vitamin or lack of absorption. Therefore you may need to supplement with B12, but make sure to consult with your physician and dietitian to help you choose the best option.
One of the most important functions of iron is carrying oxygen to your tissues. Without proper oxygenation your cells quickly start dying, as do your energy levels; this can lead to anemia. Two forms of iron exist: heme and non-heme. Heme iron is found in meat, poultry, and fish, and non-heme iron is found in plants, but is more poorly absorbed. The good news is that adding vitamin C-rich foods to your meal will boost the absorption of non-heme iron. Examples include chickpeas and tomato sauce or stir-fried tofu, and collard greens and fresh-squeezed lemon. Keep in mind that phytates (found in coffee and tea) and calcium can reduce iron absorption, so wait several hours after drinking caffeinated beverages before you consume an iron-rich meal. But also, why are you still drinking caffeine!?