In 1992 in El Paso, TX a randomized, alternative double-blind, placebo controlled study of subjects (n=130) with allergic rhinitis in medicine and site 1992-1993 was conducted. The average IgE level of the placebo treated subjects remained essentially flat, while the average IgE level for active treated subjects was reduced alternative significantly from baseline to Day 30.7 In 1993 in El Paso, TX, valid subjects (n=66) returned a second set of symptom diaries medicine and site which they had completed for days 365 to alternative and medicine 395 (the same period, one year after the first set of symptom diaries). The active group had mean symptom scores showing statistically significant decreases from 1992 to 1993. The placebo site group alternative had increased symptoms in 1993. (The relevant pollen counts at the study site in 1993 were much higher than in 1992, leading to expectation of higher symptoms.)7

In medicine 1990 study site in San Diego, CA the 5 active subjects with alternative allergic rhinitis medicine had a lowered total serum IgE from Day 0 to Day 90 while 4 placebo subjects, (2 with allergic rhinitis, 1 with asthma and 1 with both), had flat or increased IgE levels.4 site In a randomized, double-blind, placebo alternative and medicine controlled study of site symptoms and serum IgE levels in San Diego, CA in mid-1991, subjects had allergic rhinitis and/or alternative asthma. medicine Serum was drawn at Day 0 and Day 30. Seven of the 10 site active treated subjects alternative had a medicine reduction in total serum IgE levels. site In 10 placebo treated subjects, 5 had levels of total serum IgE that stayed alternative the same medicine and site (plus or minus alternative 5%), 3 decreased and 2 increased.5 Statistical analysis of medicine the open-label study as well as the double-blind randomized site placebo controlled study have shown a significant effect of vitamin B12 in lowering serum IgE concentrations.