Analysis of 437 human blood samples has shown that when the plasma-reduced ascorbic acid level (VITAMIN C) falls below 1 mg/100 ml, the whole blood histamine level increases exponentially as the ascorbic acid level decreases. When the ascorbic acid level falls below 0.7 mg/100 ml, there is a highly significant increase in the blood histamine level. Oral administration of ascorbic acid (1 g daily for 3 days) to 11 selected volunteers resulted in a reduction of the blood histamine level in every instance.
One gram of Vitamin C should not be taken all at once. Taken in large amounts, Vitamin C has a very short half life. It gets taken out by the kidneys and excreted almost immediately.
In the article above, 0.5 gram of Vitamin C was taken twice a day. Extended release would be better.
At very high levels Vitamin C becomes a mast cell degranulator (I had read that about a month ago and after doing some math figured out that the concentration that caused degranulation was higher than normal levels that could be reached with most supplements. I have to find the reference for this.).
When there's very low levels of Vitamin C, the kidneys recognize that and excretion goes down to nil. That's why it takes so long for scurvy to occur even though there's no intake of Vitamin C in the diet for months.