Proof of Identity. Proof of identity must be presented with all passport applications. Acceptable forms of identification include a passport, naturalization certificate, driver's license, military ID card or other current government-issued ID. A photocopy of the identity documents also must accompany the passport application.
Betaine, or TMG, is also involved in the manufacture of carnitine, and helps protect the kidneys from damage. Betaine HCl, or betaine hydrochloride, is an supplemental, chloride-salt form of betaine that is useful as a digestive aid.
Where to Find It. Dietary sources of betaine include fish, beets, and legumes. Betaine is most widely available as betaine hydrochloride (betaine-HCl), but that form is used primarily as a source of hydrochloric acid for people with hypochlorhydria (low stomach acid). The forms used specifically to provide betaine are betaine citrate and betaine aspartate.