Vitamin D Increases Testosterone

Low levels of vitamin D are linked to low blood testosterone. An Austrian study showed that supplementing vitamin D (3,000 IU per day) for one year increased testosterone by 20 percent and the biologically active free testosterone by 17 percent. Vitamin D is produced by the body via a reaction involving sunlight and is consumed in the diet in meat products or fortified foods. It is critical for bone health but is also important for immune system function. The increased incidence of colds and flu during the winter may be due to reduced levels of vitamin D. Several studies also found a link between low vitamin D levels and an increased risk of cancer. Testosterone is critical for muscle hypertrophy. (Hormone Metabolic Research, 43: 223-225)