Taking more than 200 mg of vitamin B6 supplements can result in sensory neuropathy (pain and numbness), although no similar finding have been made for food consumption possibly due to the existence of three types of B6. The US Food and Nutrition Board of the Institute of Medicine recommends no more than 100 mg per day be taken. Taurine has no known toxicty and is readily excreted.

Vitamin B6 is found in yeast, vegemite, dill weed, wheat germ or bran, pistachio nuts, garlic, frog legs, curry powder, fish (tuna, salmon, garfish), liver (ox, chicken, duck), seeds (sesame, linseed), breakfast cereals, and while bananas and potatoes have lower levels they can impact on B6 levels because on the quanties consumed. Vitamin B6 content is significantly reduced by cooking or processing. Taurine is found in high quanties in meat, fish, eggs, dairy products and some energy drinks. For vegans certain seaweeds are the only vegetable source of taurine, vegans tend to have low taurine levels.

1. Vitamin B6 Jane Higdon The Linus Pauling Institute http://lpi.oregonstate.edu/infocenter/vitamins/vitaminB6/ [Yet another good overview from the Linus Pauling Institute.]
2.  Taurine: a conditionally essential amino acid in humans? An overview in health and disease R. Lourenço and M. E. Camilo Nutr. Hosp. (2002) XVII (6) 262-270 www.grupoaulamedica.com/web/nutricion/pdf/062002/02_Taurine.pdf [A good, easy to follow, if somewhat technical outline of the role of taurine. Those wishing a short introduction may prefer the Wikipedia entry.]
3. Taurine Wikipedia http://en.wikipedia.org/wiki/Taurine [Effective outline on the role of taurine, more up to date than the previous article, shorter but not as easy to read]
4. There's A Pill For That I: Taurine Melissa McEwan Hunt Gather Love posted 26/3/2010 http://huntgatherlove.com/content/theres-pill-i-taurine [an exploration of the possibility of taurine deficiency, even though it is manufactured inside the body]
5. Testing of chelating agents and vitamins against lead toxicity using mammalian cell cultures Anna B. Fischer, Cristine Hess, Tilo Neubauer and Thomas Eikmann Analyst, January 1998, Vol. 123 (55-58) www.rsc.org/delivery/_ArticleLinking/DisplayArticleForFree.cfm?doi=a705518h&
   JournalCode=AN [Found that in cell cultures B6 inhibits lead uptake on a cellular level and reduces cytotoxicity]
6. Influence of Pyridoxine (Vitamin B6) on Lead Intoxication in Rats Sushil K. Tandon, Swaran J.S. Flora and Surendra Singh INDUSTRIAL HEALTH  Vol.25 , No.2(1987)pp.93-96 www.journalarchive.jst.go.jp/english/jnlabstract_en.php?cdjournal=indhealth1963&cdvol
   =25&noissue=2&startpage=93  [Found that B6 reduced levels of lead in the blood, kidneys and liver but not the brain]
7. Antioxidant Effect of Taurine Against Lead-Induced Oxidative Stress H. Gürer, H. Özgünes, E. Saygin and N. Ercal Arch of Env Cont Tox Vol 41, No 4 Nov, 2001 www.springerlink.com/content/8dckmhb9ur01tgdh/ [Finds that taurine has no impact on blood lead but did have neurologically protective properties]
8. SimSun">Influences of different developmental periods of taurine supplements on synaptic plasticity in hippocampal CA1 area of rats following prenatal and perinatal lead exposure Shan-Shan Yu, Ming Wang, Xin-Mei Li, Wei-Heng Chen, Ju-Tao Chen, Hui-Li Wang and Di-Yun Ruan BMC Developmental Biology 2007, 7:51doi www.biomedcentral.com/1471-213X/7/51 [Demonstrates the importance of taurine to brain development if lead exposure occurs]
9. Selection of Nutrients for Prevention or Amelioration of Lead-Induced Learning and Memory Impairment in Rats Guangqin Fan, Chang Feng, Yu Li, C Wang, J Yan, W Li, J Feng, X Shi and Y Bi Annals of Occup Hygiene 2009 53(4):341-351 http://annhyg.oxfordjournals.org/cgi/content/abstract/53/4/341 [Shows that in combination with methionine, taurine can protect against lead-induced brain damage, while taurine can also repair some lead-damaged memory and learning functions]