• Vitamin B18:
  • Vitamin B19:
  • Vitamin B20: carnitine
  • Vitamin B21:
  • Vitamin B22: often claimed as an ingredient of Aloe vera extracts but also in many other foods. Claimed by one source to be vitamin B12b-δ.[citation needed]

Note: B16, B17, B18, B19, B20, B21 & B22 do not appear to be animal factors but are claimed by some naturopaths as human therapeutic factors.