No idea sorry. Maybe go to a reputable site to research. Holland and Barratt or Boots. What about your local chemist, could you phone them and ask. If you're isolating they can bring it to you.
I've had low B12 and get best results from a liquid supplement from Vitacost. It absorbs best under your tongue and I get better absorption from the liquid.
You take the number of drops to get your dosage, hold under the tongue for 1 minute then swallow. Vitacost is a reliable online company, recommended by my Dr. My B12 has stayed at good levels since starting this supplement.
Super B Complex sold by CVS is what I take, along with 800-1000 mg. of Vitamin E (recommended by my doctor, 1000 mg. of Milk Thistle to detox and eliminate dairy and red meat).
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