The Best Vitamin D Supplement

Get a much-needed boost without the additives

The 30-Second Review

The best vitamin D supplements are made with vitamin D3, contain minimal additives, and are certified by multiple third-party labs to ensure both purity and potency. To find our top picks, we consulted with doctors and nutritionists from across the country, read through hundreds of ingredients labels, and utilized the results from three different independent lab tests.

Top Picks
Best Value

With high marks from two independent labs for product purity and dosage accuracy, Kirkland Signature offers a high-quality vitamin D3 supplement at the lowest price we found — $0.02 per serving.

Drugstore Pick

Less of a bargain, but still reasonably priced at $0.06 per serving. Nature Made received just as much third party praise as the Kirkland Signature option and is sold in nearly every drugstore.

The Best Vitamin D Supplements

About one-third of Americans don’t get enough vitamin D. And as researchers continue to uncover the many roles vitamin D plays in our health, it has become increasingly obvious that it’s important we get enough — and a quality vitamin D supplement is the easiest way to do that.

Our Top Pick

Kirkland Signature Extra Strength Vitamin D3 2000 IU Includes 2,000 IU of vitamin D3 and an impressive list of third-party certifications.

Our top pick is Kirkland Signature Extra Strength Vitamin D3 2000 IU. One pill contains 2,000 IU of vitamin D3, and its purity and label accuracy are certified by both the United States Pharmacopeial Convention and Labdoor, two reputable third-party supplement watchdog groups. It’s only $0.02 per serving, too.

A Close Runner-up

Nature Made D3 1000 IU A lower dose for 4 more cents per supplement.

Nature Made received just as much praise from third party test labs. The only difference between them: one Nature Made supplement contains 1000 IU of vitamin D. That’s half as much as Kirkland Signature, for three times the price.

While we don’t recommend paying more for a nearly identical product, Nature Made scores points for its availability. You can find it nearly anywhere with a pharmacy. If you prefer to buy your supplements in stores, or just want a lower dose, Nature Made Vitamin D3 is the way to go.

Our Pick for the Best Vitamin D Supplement

Best Value

Kirkland Signature Extra Strength Vitamin D3 2000 IU Includes everything you could want in a vitamin D supplement — and nothing you don’t — for the lowest price.

Kirkland Signature Extra Strength Vitamin D3 stood out because it met all of our criteria, for the best value. To start, we liked the short list of ingredients: 2,000 IU of vitamin D3 (as cholecalciferol, which mimics the way the body naturally processes vitamin D), soybean oil (rich in heart-healthy polyunsaturated fats), plus gelatin, glycerin, and water for the softgel capsule.

Kirkland Signature even earned kudos from not one, but two independent labs. Its label bears the USP symbol, arguably the gold standard for product testing. USP certification is recognized around the world.

If product quality, minimal additives, and accurate labeling aren’t enough, Kirkland Signature Extra Strength Vitamin D3 is a good value, too. At about $0.02 per serving, it was less than half the cost of our other top contenders.

We loved the Costco-sized bottle, which contained 600 softgels that were as small as any we tested. After all, if you’re going to make vitamin D supplements a part of your daily routine, you might as well make it easy on yourself: one tiny pill that’s easy to swallow, in a bottle that will last for a good 20 months. At $7.30 per year, Kirkland Signature Extra Strength Vitamin D3 is an inexpensive way to stay up on your vitamin D intake.

The only drawback? If you prefer to purchase your vitamin supplements in stores, you may be out of luck. The Kirkland Signature brand is exclusive to Costco, which requires it’s shoppers to purchase a monthly membership fee.

Best Drugstore Pick

Nature Made D3 1000 IU A few more cents per serving for nearly identical ingredients, but available in more stores than Kirkland Signature.

We liked Nature Made D3 tablets for many of the same reasons as Kirkland Signature: It’s the only other D3 supplement tested by both USP and Labdoor to ensure purity and potency, plus it includes soybean oil to help boost absorption. But unlike Kirkland Signature, a Nature Made bottle of 250 pills costs about $15 (8 more cents per serving). In other words, you’ll pay more money for fewer supplements.

Nature Made also contains 1000 IU of vitamin D per pill (half as much as Kirkland Signature). Our experts recommend 2000 IU per day to most of their adult patients. If your doctor agrees, you’ll need to take two pills per day. But the tablets are tiny, and a lower dose means you can easily take more or less vitamin D as needed.

Both brands are available through Amazon, but if you prefer to buy your supplements in a brick-and-mortar store, you can find it at grocery stores and pharmacies nationwide including Target, Walgreens, and Safeway.

Did You Know?

Most people aren’t getting enough vitamin D.

An estimated 41% of US adults are vitamin D-deficient. And that has serious long-term effects. “Without vitamin D you won’t absorb calcium in your gut, which leads to an increase in bone loss,” says Dr. Feuerstein. “But vitamin D goes so far beyond that. We have vitamin D receptors in nearly all the tissues of the body, and we’re learning about its effect on cancer, heart disease, multiple sclerosis, and in autoimmune disease.” Shuck adds that “vitamin D also has other key functions in the body, such as helping to maintain normal immune system functioning.”

It’s difficult to get adequate vitamin D through diet alone.

There are food sources of vitamin D, notes nutritionist Shereen Lehman: “Oily fish like salmon and tuna have some vitamin D, and eggs do as well. Mushrooms like maitake and chanterelle can be a good source, as can portabella mushrooms grown in UV light. Otherwise, look for foods fortified with vitamin D like milk, breakfast cereals, and many brands of nut milk.”

Vitamin D-rich Foods
IU per Serving
Maitake mushrooms
Swordfish, 3 ounces
Sockeye salmon, 3 ounces
Chanterelle mushrooms
Canned tuna fish, 3 ounces
Orange juice fortified with vitamin D, 1 cup
Milk, 1 cup
Egg, 1 yolk

But can you get enough D just from food sources? That depends on how hungry you are. The National Institutes of Health (NIH) found that even foods rich in vitamin D require multiple servings to meet the recommended 600 IU per day.

And more sun exposure comes with its own risks.

Some medical researchers, like Dr. Holick, recommend getting 15 minutes of unprotected sunlight per day — in the middle of the day when the sun is brightest. And Dr. Weil recommends 10 minutes of sun per day. But the American Academy of Dermatology disagrees, and suggests we use skin protection (clothing and sunscreen with an SPF of 30 or higher) every time we’re out in the sun, to prevent skin cancer.

So what’s the right answer? We suggest checking with your doctor to find out what’s right for you.

A simple test will tell if your vitamin D level is low.

Many doctors routinely check vitamin D levels during a patient’s annual physical exam. A simple blood test, called the 25(OH)D, will determine the amount of vitamin D stored in your body from all sources, including sun, diet, and supplements. In fact, the test measures stored vitamin D as far back as 15 days, which makes it the ideal way to get an accurate measurement of your vitamin D level.

If your doctor doesn’t already check your vitamin D levels during your annual exam, don’t be afraid to ask for the test.

Another option: a home testing kit for under $70 from the Vitamin D Council. You prick your finger and place a drop of blood on blotting paper, and then send it to the lab, which will mail you your results.

If your test determines that you’re deficient in vitamin D, Dr. Feuerstein suggests working with your medical provider to determine the best dosage — and getting tested every six months until you reach your goal. He routinely tests his patients twice a year to determine if their vitamin D level changes from summer to winter.

The Bottom Line

Best Overall

Kirkland Signature Extra Strength Vitamin D3 2000 IU Includes 2,000 IU of vitamin D3 and an impressive list of third-party certifications.

Unless you’re a professional surfer, chances are you don’t get enough year-round sun to keep your vitamin D levels where they should be. Check with your doctor to see if vitamin D supplements are right for you, especially if you are pregnant, breastfeeding, or have a medical condition. Since it’s tough to get enough vitamin D from food, adding a vitamin D supplement to your daily routine could be a good — and inexpensive — way to protect yourself from bone loss and a host of other potential health problems.