Is there a practical guide to inexpensive home testing? None that I know, might exist though. I mean, you can buy dead cheap properly working test kits for MDM

Is there a practical guide to inexpensive home testing? None that I know, might exist though. I mean, you can buy dead cheap properly working test kits for MDMA for instance, then why not for B12 you'd wonder. But rather than testing the B12 itself you might just (or also) test if you have enough of it. Many vegans I know make a yearly appointment with their doctor for a blood test looking for defficiencies in a number of substances. Most are always fine btw. Oh and google came up with this: http://www.testcountry.com/products.html?product=1883 http://www.testcountry.com/products.html?product=1883. Again, hard to tell if it's ok - but you could compare it with blood test results. Then again, blood test might be cheaper than this kit.