I think my allergies are much better using Vitamin C, as Calcium Ascorbate I was recommended. I have had a bit of issues adapting to 1/2 tsp of the powder (with a bit of stomach discomfort, cramping) so I cut back to just the 1/4 tsp. Doing ok so far, haven't noticed a big difference in the occasional heart palpitation. Just when I feel sort of anxious it happens. Vit C has helped others with A-fib so thought I'd try it. Plus other ways of relaxing, healthy ways :) I got the 500mg Now brand and I just do it 2 times a day, morning and night.
I started taking increased doses of Vitamin C a number of years ago at my doctor's recommendation for a tendency to bruise easily. One of the other unexpected benefits is that my sinuses cleared up. I used to wake up sneezing and would continue throughout the morning, sometimes through the entire day, year round. After experimenting with different dosages, I am now on a maintenance level of 2000 mg of Vitamin C daily and this keeps my allergies under control usually 50-51 weeks out of the year. Occasionally, I may have a flare-up and need something else. When that happens, I stir 1 teaspoon of ground Turmeric into an 8 oz. glass of water and drink it. Within 15 minutes, I am breathing freely once again and no more sneezing!