  Profound vitamin B12 deficiency is a known cause of disease, but the role of
low or intermediate levels of B12 in the development of neuropathy and other
neuropsychiatric symptoms as well as the relationship of eating meat and B12
levels is unclear. Here we use food-related internet search patterns from a
sample of 8.5 million US-based people as a proxy to B12 intake and correlate
these searches with internet searches related to possible effects of B12
deficiency. Food-related search patterns are highly correlated with known
consumption and food-related searches (Spearman 0.69). Awareness of B12
deficiency was associated with a higher consumption of B12-rich foods and with
queries for B12 supplements. Searches for terms related to neurological
disorders were correlated with searches for B12-poor foods, in contrast with
control terms. Popular medicines, those having fewer indications, and those
which are predominantly used to treat pain are more strongly correlated with
the ability to predict neuropathic pain queries using the B12 contents of food.
Our findings provide evidence for the utility of using Internet search patterns
to investigate health questions in large populations and suggest that low B12
intake may be associated with a broader spectrum of neurological disorders than
currently appreciated.
