Dr. Anthony’s Notes: Vitamin D has about 100 other beneficial body functions outside of it's impact on testosterone. Make sure you take the active Vitamin D3 (not D2 – from plant sources!) It’s also advisable to get 20 minutes of sunshine daily (weather permitting) – without sunscreen. Verdict: this is one of the natural testosterone supplements that work. Best Food Sources of Vitamin D3: Wild Alaskan Salmon (#1), Sardines, Eggs How To Take Vitamin D3: Using 3000-5000IU of Vitamin D3 per day is a good safe, research supported dose. Your physician can also test your blood for D3 levels for more precise monitoring.
We kept it simple, and followed the premise of testosterone boosters: testosterone affects muscle gain, weight loss, and libido, so by increasing the amount of testosterone in the body, we can improve on each of those goals. This meant that we looked for ingredients proven to increase testosterone levels, not ingredients that might increase libido or help build muscle mass independently of testosterone (like having a healthy diet and feeling good about yourself). In addition, we dove deep into the specific ingredient lists of our finalists and cross-checked them against WebMD and the National Institutes of Health (NIH) database to make sure that they did not contain ingredients known to be harmful.
Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5α-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5α-reductase. DHT binds to the same androgen receptor even more strongly than testosterone, so that its androgenic potency is about 5 times that of T.[114] The T-receptor or DHT-receptor complex undergoes a structural change that allows it to move into the cell nucleus and bind directly to specific nucleotide sequences of the chromosomal DNA. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing the androgen effects.

Among the changes which occur with aging are those that affect several aspects of the endocrine system which reduces its secretions to varying degrees in different individuals. These reductions in secretions are identified by a poor but widely recognized appellation, the “pauses”: menopause (decreased ovarian function), adrenopause (decreased adrenal function, especially with regard to dehydroepiandrosterone secretion), somatopause (decreased growth hormone production), andropause (decreased hypothalamic-pituitary testicular function with diminished testosterone availability and impaired spermatogenesis) (Lamberts 1997).
Get plenty of vitamin D. Vitamin D is a very important nutrient when it comes to testosterone production. This makes sense when you realize that vitamin D acts more like a steroidal hormone than it does like any typical vitamin. A 2010 study looked at the relationship between vitamin D supplementation and testosterone levels in men and found that those with higher levels of the vitamin also had higher levels of testosterone in their blood.[12] Vitamin D is made by human skin in response to intense summer sunshine, but a lack of going outdoors has triggered near epidemic levels of deficiency in American teenagers. Compounding this problem is that most northern states don't get enough sunshine to trigger vitamin D production for many months of the year.

Testosterone levels generally peak during adolescence and early adulthood. As you get older, your testosterone level gradually declines — typically about 1 percent a year after age 30 or 40. It is important to determine in older men if a low testosterone level is simply due to the decline of normal aging or if it is due to a disease (hypogonadism).