Vitamin D is difficult to get from food, and most people do not get enough sunlight exposure, which is why many take a vitamin D supplement, explains Everyday Health. A study found that men with low levels of vitamin D are twice as likely to have a heart attack then men with normal levels. Other studies suggest that a deficiency in this vitamin can increase the risk for colon cancer and can cause weak muscles and bones.
Folic acid is another important vitamin that is in the class of B vitamins, states Everyday Health. This vitamin can protect men from heart disease by preventing the buildup of homocysteine, which can lead to heart and blood vessel disease when in excess. Too much folate can increase the risk of colon cancer, which is why it should only be taken if homocysteine is low.
Vitamin B-12 is essential for a healthy nervous system, notes Everyday Health. Older men have an increased need for this vitamin, and it can alleviate some cases of depression and dementia. It is easy to get this vitamin from proper nutrition such as fortified cereals as well as from supplements, but should only be taken with a doctor's recommendation.