You need vitamin C for healing wounds, forming collagen and acting as an antioxidant to keep free radicals from damaging your cells. Both vitamin C powders and vitamin C pills have their benefits, and which you should choose will depend at least in part on your own personal preferences and needs.
Absorption and Bioavailability
Synthetic ascorbic acid tends to be just as bioavailable as natural ascorbic acid, and powders, pills and chewable forms of vitamin C are also equally bioavailable, according to the Linus Pauling Institute. Slow-release forms of vitamin C may not be as well-absorbed, however, as study results are mixed with this form of vitamin C. Powders that combine calcium ascorbate with vitamin C metabolites, such as Ester-C, haven't been proven to increase absorption of vitamin C.
Ease of Use
Choosing a powdered supplement instead of a pill may be better for those who have difficulty swallowing. Powdered forms also make it easy to adjust your dose if you need to.
It's important to store vitamin C powder somewhere very dry, however, not in your bathroom or kitchen, or the powder in the open packages could start to become unstable and form clumps. In this case, it won't be as effective.
If you don't have difficulty swallowing pills, it may be easier to choose this form of vitamin C supplement, as your dose is already premeasured and you don't need to mix it with liquid to take it. Some people also find the taste of powdered vitamin C supplements to be unpleasant.
Potential Side Effects
Chewable tablets and powdered forms of vitamin C supplements expose your teeth to more acid than vitamin C pills, which can harm your teeth unless you choose a nonacidic version and rinse your mouth out well with water afterward.
If the acidity of regular vitamin C supplements bothers you, a buffered supplement in the form of a mineral ascorbate, which combines ascorbic acid with a mineral like calcium or potassium, may be less likely to cause side effects, including upset stomach or diarrhea, although more research is necessary to verify this potential benefit.
Very high doses of vitamin C from supplements in any form, such as those above 2 grams per day, could cause diarrhea, nausea, stomach cramps, headache, flushing or an increased risk of kidney stones.
Other Potential Considerations
Any vitamin C supplement may interact with blood-thinning medications, so speak with your doctor before adding these supplements to your daily routine.
Whichever form of vitamin C you take, look for one with the United States Pharmacopeia symbol on the bottle. ConsumerLab.com noted that 27 percent of the vitamin C supplements it tested didn't contain the amount of vitamin C listed on the label, and USP-verified products have been tested for vitamin content and absorbability.