What can help low testosterone?

Vit D. Low t has many causes, but low vitamin d may be the easiest and most healthy option to correct it. The link between vit. D and testosterone is not totally clear, but many individuals have low d that when addressed their t levels retrain to normal. Before just adding vit d, have other causes for low t evaluated by your doctor. Additionally, adding muscle will improve t.
Being healthy. Low testosterone can be caused by a number of things. Most common culprits are: obesity, obstructive sleep apnea, medications like opiates/narcotics, chronic illness, testicular disorders. See your doctor for discussion.