At times of lower dietary intake of B12, its rate of absorption from food into the bloodstream rises, thus maximising available supplies. For many years, it was thought that edible seaweeds, fermented soya foods and spirulina contained high levels of B12. The amount of B12 in these foods was measured using bacterial growth as an indicator and it measured a whole family of 'chemical look-alikes'. A newer test, called a differential radioassay, is thought to specifically measure the forms of the vitamin which the body can use. The following companies produce a range of supplements including vitamin B12.
Companies do make ingredient changes so please check products before purchase.
Cytacon B12 Liquid Re-analysis of vitamin supplements using modern methods indicate that these are reliable sources of genuine vitamin. The researchers also questioned the efficicacy of B12 absorption from multi-vitamin tablets, suggesting other constituents such as copper and iron may inhibit B12 absorption. Other Sources of B12 Grains, nuts, pulses, vegetables and other natural plant foods do not contain B12, unless they are contaminated with B12-producing bacteria from the soil. He discovered that they grew their vegetables in human manure, did not wash them carefully, and thus obtained the vitamin from bacterial contamination. Some drinking water may also contain B12.