The Best Vitamin C Supplement
When it comes to the best vitamin C supplement, there's no one-size-fits-all. The nutrient can be derived from a variety of sources. So we set out to find the best pick for each source: synthetic ascorbic acid, natural ascorbic acid, and mineral ascorbates. After talking to multiple doctors and nutritionists, analyzing the results of multiple third-party lab tests, and reading hundreds of ingredients labels, we found our winners.
Pure, powdered vitamin C in the form of synthetic ascorbic acid. Its purity and potency are certified by multiple third-party labs.
Doctor’s Best Vitamin C
Another synthetic option, in convenient tablet form — and with fewer fillers than most tablets.
More expensive than our top pick, but natural rather than synthetic vitamin C.
Nature’s Way Alive Vitamin C
A natural option for sensitive stomachs. Contains mineral ascorbates rather than ascorbic acid.
Ascorbic acid (a.k.a. vitamin C) is a powerful antioxidant. It’s also essential in helping our bodies repair and prevent injuries and illnesses. But humans can’t produce it on their own; that’s why we need to get vitamin C from outside sources like fruits, vegetables, and — you guessed it — supplements.
And when it comes to supplements, you’ve got options. You can choose a product made from natural (food-based) ascorbic acid or synthetic (made in a lab) ascorbic acid. You can also go with a mineral ascorbate — a supplement in which the ascorbic acid has been “buffered” with minerals like sodium or calcium to lessen its acidity. No single type offers a clear advantage, so our top picks include a mix of all three.
Our favorite is Bulk Supplements Vitamin C Crystallized Powder. It consists of only one ingredient: Ascorbic acid (in other words, pure vitamin C). It is the highest-ranked vitamin C supplement on Labdoor, a reputable third-party testing lab, and boasts the use of Good Manufacturing Practice (GMP) standards, a voluntary set of procedures established by the Food and Drug Administration as a way of ensuring safe and consistent products. Because it’s a powdered supplement, you can easily fine-tune your dosage, and at $0.01 to $0.02 per serving, it’s also one of the cheapest options on the market.
If you’re looking for a natural ascorbic acid option — that is to say, vitamin C that’s not made in a lab — we recommend Nature’s Way Alive Vitamin C. This powder uses four organic fruits as its source of vitamin C. It does have a slightly dry, bitter flavor that makes it difficult to drink, and it’s one of the more expensive supplements, at $0.60 per serving. But compared to the other natural options we looked at, Nature’s Way had the least amount of added sugar and filler ingredients.
Source Naturals Vitamin C gets our vote for the top mineral ascorbate supplement. This product gets its vitamin C from sodium ascorbate and may be a better fit for people who experience stomach upset from ascorbic acid. At around $0.08 per serving, it’s a little more expensive than our top ascorbic acid pick, but we think the price is still reasonable. However, 1,000 mg of sodium ascorbate contains about 100 mg of sodium, so you may want to avoid this product if you’re watching your sodium intake.
If measuring a powdered supplement daily sounds too inconvenient, we recommend Doctor’s Best Vitamin C, which comes in tablet form and is made from synthetic ascorbic acid. This supplement is easy to take with your other vitamins or swallow on the way out the door. Of all the tablets we considered, it contained the least amount of fillers — and received one of the highest quality ratings from Labdoor. At $0.12 per serving, it is a slightly more expensive option. But the convenience of not having to measure out your daily dose of vitamin C might be a worthwhile tradeoff.
How We Found the Best Vitamin C Supplement
We started by gathering a list of vitamin C supplements widely available online or in stores, pulling from sites like Walgreens, GNC, and Amazon. Because we wanted to look just at vitamin C, we avoided multivitamins. Even so, we were left with a list of 162 contenders.
We were also left with a lot of variety. In addition to varying sources of vitamin C, the supplement comes in a plethora of forms. Powders, capsules, and tablets were the most common, but we also found gummies, chewable tablets, drink mixes, and even a flavored spray.
We got rid of anything with questionable ingredients.
So we began by ditching supplements that used artificial colors (ruling out several chewable tablets) or proprietary blends. Proprietary blends were a particular sticking point: The FDA doesn’t require manufacturers to list how much of each ingredient they use in their proprietary blends, and that means you don’t know exactly what you’re swallowing — which could be cause for concern if you’re taking a vitamin C supplement daily.
Deanna Latson, clinical nutritionist and co-founder of health product company ARIIX also pointed out to us that any product not listing the source of its vitamin C is actually breaking labeling laws. So we decided to cut any vitamin C supplements that didn’t name their source clearly on the label.
Next, we eliminated products that contained any of the ingredients below. These occupy a gray area — they’re probably OK to consume, but there are plenty of less-questionable alternatives:
- Titanium Dioxide: This is an FDA-approved ingredient used as a colorant in tablets. However, the International Agency for Research on Cancer considers it “possibly carcinogenic to humans,” so we cut supplements that contained it.
- Maltodextrin: Maltodextrin is used as a filler, and while it has no serious health risks, it does have a glycemic index higher than table sugar. There's no reason you need it in a vitamin C supplement — and there are plenty of products without it.
- Talc: Talc is used to dust molds during the manufacturing process and is completely harmless. There is some concern that talc can easily become contaminated with asbestos as it’s mined, however, so to be on the safe side, we cut any products that used it.
We cut any supplements without third-party certifications.
Since the FDA doesn’t regulate dietary supplements, it is up to manufacturers to maintain the integrity of their products. One way they can do this is by allowing third-party labs to conduct tests.
When we talked with Arielle Levitan, MD, co-founder of Vous Vitamin and co-author of The Vitamin Solution: Two Doctors Clear the Confusion about Vitamins and Your Health, she explained that third-party verifications are “independent ways manufacturers can demonstrate that they have gone the extra step to verify the purity of their product and to certify that what’s in the bottle is actually in the bottle.”
So we looked for supplements that were verified by organizations like Consumer Lab, The United States Pharmacopeial Convention(USP), Labdoor, and The National Sanitation Foundation (NSF), giving higher scores to products with verifications from more than one group.
We looked for confirmation of two things:
- Label Accuracy: Labdoor found that one out of every three vitamin C supplements it tested varied from label claims by at least 30 percent. Some products had 60 percent less vitamin C than advertised, and some had 116 percent more. So we relied on third-party testing to make sure our top picks matched their label claims within a decent margin (about 10 percent).
- Purity:Vitamin C supplements sometimes contain traces of heavy metals, like lead, mercury, cadmium, and arsenic. So we turned to third-party labs to make sure that none of our top picks contained toxic levels of contaminants.
From here, we looked for products that exceeded our minimum standards: supplements that had approvals from multiple third-party labs, say, or supplements with exceptionally high Labdoor ratings. We also looked back through the labels for options with the smallest amount of filler ingredients. This left us with 10 possible contenders — so we did a little hands-on testing for things like smell, appearance, and taste.
What we tested:
- Bulk Supplements Vitamin C
- Doctor’s Best Vitamin C
- Dynamic Health Liquid Vitamin C
- Nature’s Bounty Pure Vitamin C-500
- Nature Made Vitamin C
- Spring Valley Vitamin C
- Natural Factors Vitamin C Fruit Chews
- Nature’s Way Alive Vitamin C
- Nature’s Answer Liquid C
- Source Naturals Vitamin C
Once we began opening bottles and jars, several contenders got immediate low marks for an off-putting taste or smell. Nature Made Vitamin C left a chalky residue behind in our mouths that one tester said reminded her of prescription medication. We also weren’t wild about our two liquid options, Dynamic Health Liquid Vitamin C and Nature’s Answer Liquid C, which had to be kept refrigerated after being opened. And while we had high hopes for Natural Factors Vitamin C Fruit Chews, they ultimately didn’t make the cut either: they contained added sugar and tasted chalky, not exactly a winning combination.
Our Picks for the Best Vitamin C Supplement
If you’re looking for a vitamin C supplement that uses ascorbic acid, our top pick is Bulk Supplements Vitamin C Crystallized Powder.
“Bulk Supplements” is such a vague name that it might sound like something you’d buy out of an unmarked van, but we promise this supplement is more than trustworthy. Because it’s a powder, it has none of the filler ingredients found in tablets: It contains nothing but ascorbic acid. It’s also the highest-ranking vitamin C supplement at Labdoor, scoring 100 percent in label accuracy, nutritional value, and ingredient safety. And it’s produced according to GMP standards.
Since this supplement is a powder, you can choose your dose. The package recommends 1,000 mg daily, but the measurement guidelines on the label made it easy for us to adjust how much we took. It doesn’t taste terrible, either — compared to Nature’s Way Alive Vitamin C (our top natural ascorbic acid pick), Bulk Supplements was by far the more palatable option. Our testers thought it was reminiscent of lemon water, with a bit of a sour punch at the end. The package itself is a bit large, but no bigger than your average bag of granola or nuts. As long as you have a dry, cool, and dark space for it, you should be set.
One of the main selling points, for us, was price: Bulk Supplements is one of the cheapest vitamin C options on the market. One 1 kg bag contains roughly 1,000 servings (assuming each serving is 1,000 mg). This breaks down to roughly $0.02 per dose.
This is a synthetic ascorbic acid supplement, which might be a turnoff for some people. In this case, “synthetic” just means that the ascorbic acid is derived from fermented sorbitol — a sugar alcohol that often comes from corn syrup or fruit. But if you’re looking for a more natural product, we’d suggest Nature’s Way Alive Vitamin C or Source Naturals Vitamin C.
If your vitamin C supplement doesn’t come from ascorbic acid, it’s probably derived from mineral ascorbates. These are the salts of ascorbic acid and can include sodium ascorbate, calcium ascorbate, and potassium ascorbate. Some people prefer these options because they’re less acidic and may be easier on the digestive tract. In this case, we recommend Source Naturals Vitamin C.
Source Naturals Vitamin C is a crystallized powder that’s approved by Labdoor with an overall quality rating of 90.9 out of 100. The only reason this score isn’t higher is because the supplement contains 2,060 mg of vitamin C in each serving. That means one serving would put you over the recommended 2,000 mg daily limit. But since it’s in powdered form, we weren’t hugely concerned — you just need to be proactive about adjusting your dose.
The package recommends a 2,000 mg serving, and at $15, that’s around $0.08 per serving — a little more expensive than our Bulk Supplements top pick, but probably worth the trade-off if you’re looking for something that may be easier on your stomach. This product also smells and tastes like nothing, so it would be a simple add to the water or juice you already take with your meals.
One word of warning: When you take a mineral ascorbate, you are absorbing the ascorbic acid as well as the mineral that it came from. Since this product uses sodium ascorbate, anyone watching their sodium intake should take note. There are roughly 100 mg of sodium in every 1,000 mg of sodium ascorbate.
If you’re looking for a naturally derived ascorbic acid supplement, Nature’s Way Alive Vitamin C is a good option. This powder gets its vitamin C from fruits such as acerola, kiwi, goji, and amla. It has a 90.8 rating from Labdoor and is USDA-certified organic. According to Nature’s Way, the product is also vegetarian and gluten-free. Labdoor did find this product exceeds allowable arsenic levels by 0.001 mcg per serving, but since it passed its product purity test despite this, we think it’s still safe to consume.
We weren’t huge fans of this product’s taste, however. With a tangy flavor that is more bitter than sweet, it was exactly how we imagined unsweetened, powdered fruit would taste. Cost is another slight drawback: The serving size is 500 mg, and each serving comes out to $0.60, making Nature’s Way one of the more expensive vitamin C supplements. If you’re looking for a cheap, great-tasting product, we recommend you look at our other top picks. Otherwise, it’s hard to find another natural vitamin C powder that has more to offer.
If you don’t want to mess with powders every day and just want a tablet you can swallow with the rest of your vitamins, we really liked Doctor’s Best Vitamin C. Compared with our other top contenders, this option had the second-highest Labdoor rating (after Bulk Supplements) and contained just two ingredients, making it the purest tablet on our contender’s list. It contains only ascorbic acid, plus modified cellulose to make the vegetarian capsule. Each tablet has 1,000 mg of vitamin C, which means you probably only need one pill a day, and the cost comes out to a respectable $0.12 per serving. In fact, the only reason Doctor’s Best isn’t our top choice is because a tablet doesn’t allow the flexibility of choosing your own dose.
If you’re looking for a cheaper tablet, you can also try Nature’s Bounty Pure Vitamin C-500 at about $0.04 per serving. This option does have more filler ingredients than Doctor’s Best — but fewer than the other tablets we looked at.
The Best Vitamin C Supplements: Summed Up
Did You Know?
There are benefits to taking moderately high doses of vitamin C.
We only need about 100 mg a day — so why do vitamin C supplements come in such high doses? Turns out, there are health benefits associated with taking more, including the treatment or prevention of several diseases:
In a nutshell, 500 mg seems to be the golden number, but you’ll probably benefit from anything between 250 mg and 1,000 mg.
Although vitamin C in moderate doses helps prevent cataracts, Consumer Lab also cites a study that suggests taking 1,000 mg or more daily actually increases your risk of developing cataracts. And every source we scoured, from NIH, to Consumer Lab, to the Linus Pauling Institute and the Mayo Clinic recommended not exceeding 2,000 mg of vitamin C daily.
So what happens if you take a higher dose? Because vitamin C is water-soluble, anything the body doesn’t use is flushed out as waste. This means the consequences of overdosing aren’t severe, but we still don’t recommend it. Our best advice is to pay attention to your vitamin C intake and consult with your doctor about the dosage that works best.
We’d also suggest keeping Levitan’s advice in mind: “A lot of people are already getting some vitamin C in their diet,” she says, “so when you look at not exceeding 2,000 mg, you should look at your total intake and not just what you’re getting in the supplement.”
The jury’s still out on whether mineral ascorbates or ascorbic acid are better.
Natural ascorbic acid (derived from plants) and synthetic ascorbic acid (produced in a lab) are chemically identical. But some vitamin C supplements rely on mineral ascorbates rather than ascorbic acid. These products are often marketed as being easier on the stomach, but it’s unclear how true this is.
Both Latson and Dr. Russell Jaffe, creator of the PERQUE™ Potent C Guard™ effervescent powder and tabsules, say they prefer supplements sourced from mineral ascorbates because they’re easier for the body to absorb and they work more effectively than ascorbic acid. Plus, mineral ascorbates make it harder to exceed that 2,000 mg upper limit — the whole foods that they’re derived from typically have a lower vitamin C content. That said, the Linus Pauling Institute has found little scientific evidence that mineral ascorbates are easier on the digestive tract. There’s simply not much research on the subject.
No one seems to suggest that mineral ascorbates are actively worse, however, so if you’re concerned about acidity, you might want to give this source of vitamin C a shot.
Don't pay extra for rose hips, bioflavonoids, and timed-release capsules.
If you’ve spent time wandering the vitamin aisle, you might have noticed vitamin C supplements marketed with “extras” like rose hips, bioflavonoids, or timed-release formulas. These options supposedly increase vitamin C’s bioavailability (the amount absorbed by your body). And while none of them are harmful, they’re probably not worth paying extra for.
Rose hips are used in many supplements because, when fresh, they’re a great natural source of vitamin C. But drying and processing rose hips causes them to lose much of that potency, and there’s even some evidence that quercetin, a flavonoid found in rose hips, can inhibit vitamin C absorption when taken in high enough doses.
Bioflavonoids are a powerful antioxidant found in foods rich in vitamin C, and they’re sometimes marketed as a way to help your body absorb more of the vitamin. However, the Linus Pauling Institute says there is no conclusive evidence that bioflavonoids increase absorption.
Timed-release capsules slowly release vitamin C over a period of time, again with the hope of maximizing absorption. But the Linus Pauling institute has likewise found no evidence that timed-release formulas are more effective than traditional supplements.
Take vitamin C before you catch a cold.
The myth that vitamin C cures the common cold is unfortunately just that — a myth. Many of the sources we found agree that there is no benefit to taking extra vitamin C once you’ve already been hit with the sniffles. But taking vitamin C regularly when you’re healthy can help reduce the duration of your cold by a day or two when you do fall ill, which we think is worth the investment.