Vitamin D and Testosterone

Did You Know vitamin D3 levels are related to testosterone levels? By definition, a vitamin is a nutrient that cannot be produced by the body, but is necessary for vital functions of the body tissues and organs. Vitamin D is produced in the body when our skin is exposed to ultraviolet light. Because our bodies can manufacture vitamin D, technically it is not a vitamin, but a prehormone. The active form of vitamin D, which our bodies manufacture, called calcitriol, is a hormone. Hormones by definition can activate a cell in two ways: First, some hormones enter the cell and bind with the DNA in the nucleus. Second, some attach themselves to the cell membrane. Vitamin D (calcitriol) can do both.

Vitamin D has a whole host of positive benefits including preventing cancer, heart disease, osteoarthritis, multiple sclerosis, periodontal disease, etc. Well, now it looks as though we can add increased testosterone to the list. A Harvard study examined 1362 male participants and found a positive association between vitamin D3 levels and free testosterone. The researchers found a linear dose response association between D3 and free testosterone at lower levels (below approx. 75-85 nmol/l), reaching a plateau at higher levels.

(Clinical Endocrinology, 77: 106 – 12, July 2012) Paid subscription needed to view full article.