Here's an interesting article: (http://jn.nutrition.org/content/110/4/662.full.pdf) that discusses high whole blood histamine as a result of low Vitamin C. I found this interesting because Walsh decribes high histamine as a good indicator of undermethylation, but I guess low vit C can do the same thing.
"Clearly, ascorbic acid loading can be used as a test to determine the cause of an elevated blood histaminelevel. If the blood histamine level falls as a result of ascorbic acid administration, we may reasonably conclude that it was elevated as a result of ascorbic acid deficiency. Statistical analysis has shown that plasma reduced ascorbic acid levels below 0.7 mg/ 100 ml are associated with significantly
elevated blood histamine levels,"
Maybe this is a good reason for me to take some vitamin C supps.
"Clearly, ascorbic acid loading can be used as a test to determine the cause of an elevated blood histaminelevel. If the blood histamine level falls as a result of ascorbic acid administration, we may reasonably conclude that it was elevated as a result of ascorbic acid deficiency. Statistical analysis has shown that plasma reduced ascorbic acid levels below 0.7 mg/ 100 ml are associated with significantly
elevated blood histamine levels,"
Maybe this is a good reason for me to take some vitamin C supps.