- Does it help? If you get sufficient vitamin C from your diet (such as from a cup of tomato or orange juice), taking more from a supplement will generally not help. Nevertheless, taking high-dose vitamin C daily from a supplement during cold season can slightly reduce the risk of getting a cold, particularly if you are deficient in vitamin C, but won't help once you're sick. Vitamin C supplementation may also slightly reduce blood pressure, although it has not been shown to reduce rates of cardiovascular disease. Taking vitamin C has also been associated with a reduced risk of gout. (See What It Does)
- How much should I take? To be sure you're getting the daily requirement of vitamin C, a supplement providing roughly 50 mg to 100 mg of vitamin C is sufficient for most adults and is quite safe (see What to Consider When Using).
When higher doses are taken in hopes of reducing the risk of a cold or gout, or to slightly reduce blood pressure, a typical dose is 500 mg taken twice daily or up to 2,000 mg per day. Be aware, however, that taking more than 500 mg of vitamin C per day on a regular basis (which will saturate your blood with vitamin C) may increase your risk of developing cataracts, and taking more than 1,000 mg per day may also increase your risk of kidney stones. Diarrhea can result from a single dose of more than 2,000 mg for an adult and lower amounts for children (see Concerns and Cautions). In short, there is a risk/benefit trade-off when taking high-dose vitamin C.
- Which form is best? There are many forms of vitamin C available (ascorbic acid, sodium ascorbate, calcium ascorbate, liposomal vitamin C, etc.) but there is no compelling evidence that one is much better than another. The ascorbate forms may be easier on your stomach, but you will still run a risk of developing loose stools at a very high dose. Whole food ingredients (like lemon peel) will provide additional bioflavonoid compounds, which may be of some benefit, but are not necessary to meet your nutritional needs, and natural vitamin C, such as from rose hips, is the exact, same compound, L-ascorbic acid, found in most synthetic vitamin C supplements. As vitamin C is an acid, products formulated as capsules or tablets may be safer for your teeth than high-dose liquids, powders (mixed into liquids), chewables, or gummies. (See Forms of Vitamin C).
- Which product is best? Among the products that contained their listed amounts of vitamin C and were "Approved" in testing by ConsumerLab.com, four were chosen as CL's Top Picks for different uses, including one that provides the daily requirement of vitamin C for less than a penny.
Vitamin C Supplements Review
Find the Best Vitamin C Supplement. Tests and Reviews of Popular Vitamin C Supplements & CL's Top Picks
Vitamin C supplements compared in this review
American Health Ester-C
ChildLife Liquid Vitamin C
Dr. Mercola Liposomal Vitamin C
Emergen-C 1,000 mg Vitamin C - Super Orange
Ester-C 500 mg
Garden of Life mykind Organics Vitamin C - Organic Spray - Orange-Tangerine
Garden of Life Vitamin Code RAW Vitamin C
Jamieson Chewable C 500
Life Extension Vitamin C and Bio-Quercetin Phytosome
Nature Made C Gummies 250 mg
Nature's Bounty C 500 mg
Natures Plus Animal Parade Vitamin C - Natural Orange Juice Flavor
Nature's Way Vitamin C With Rose Hips
Rexall Vitamin C 500 mg
Signature Care Vitamin C 500 mg
Solaray Vitamin C Powder 5,000 mg
Solgar U-Cubes Vitamin C Gummies
Solgar Vitamin C 1,000 mg
Sundown Vitamin C 500 mg
Thorne Vitamin C with Flavonoids
Vitafusion Power C - Natural Orange Flavor
- Which vitamin C supplements passed testing, and which failed
- Which high-quality vitamin C supplements are also lowest cost
- What vitamin C can and cannot do for your health
- The potential advantages and differences of forms of vitamin C, such as Ester-C, sodium ascorbate, slow-release vitamin C, and liposomal vitamin C
- The value of additional ingredients, such as bioflavonoids (e.g., quercetin, dihydroquercetin, rutin, and hesperidin)
- The dosage of vitamin C used for different purposes
- The potential side-effects of vitamin C and its interactions with drugs and diagnostic tests
As a ConsumerLab.com member, you may print a copy of this report for your personal use.
You can access a special print version by clicking the "Print" icon in the upper right corner of this report. You can then use your web browser's print functions to print the whole report or just selected pages.
You may also email or post a link to this report using the web address above. Non-members using the link will see a free summary and can join to view the full report. Other means of copying or distributing this report, in part or full, are not permitted.