Vitamin D is often referred to as "the sunshine vitamin," because the body manufactures it after being exposed to the sun's rays [source: MayoClinic]. The main purpose of vitamin D is to balance calcium, but the more researchers learn about it the more they're finding additional benefits.
Sixty-one percent of the population is said to suffer from vitamin D deficiency [source: Nordqvist]. This deficiency can lead to major issues, such as obesity, diabetes, hypertension, heart attack, stroke and muscle weakness. Men who don't get outdoors much will likely find it difficult to get enough vitamin D through food. The only food sources of vitamin D are fatty fish, egg yolks and fortified milks and cereals.
Thankfully, supplementation is easy. Make sure, however, to take the recommended dosage. Since vitamin D is linked to calcium buildup, taking too much may lead to calcium in the blood, which can result in kidney stones, vomiting and muscle weakness.
Next up, a vitamin that's rising in popularity.