The Best Vitamin D Supplement
How We Found The Best Vitamin D Supplement
233 products considered
5 experts consulted
2 top picks
The Best Vitamin D Supplement
The best vitamin D supplements should be third-party tested to ensure that you’re not getting any harmful additives or contaminants. You should also make sure you’re consulting your doctor or a nutritionist to ensure you’re taking the best vitamin D supplement for your needs. To find our top picks, we consulted doctors and nutritionists from across the country, read through hundreds of ingredients labels, and utilized the results from three different independent lab tests. In the end, we found two supplements that stand the best chance of boosting your vitamin D levels.
The 2 Best Vitamin D Supplements
- Kirkland Signature Extra Strength Vitamin D3 2000 IU -
Best Value Pick
- Nature Made Vitamin D3 -
Best Drugstore Pick
The Best Vitamin D Supplements: Summed Up
Kirkland Signature Extra Strength Vitamin D3 2000 IU
Why we chose it
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.
At about $0.01 per serving, it’s less than half the cost of our other top pick. 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 $3.50 per year, Kirkland Signature Extra Strength Vitamin D3 is an inexpensive way to stay up on your vitamin D intake.
Points to consider
Requires a membership
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 its shoppers to purchase a monthly membership fee. While we did find it available for sale on Amazon, you’ll need the Costco membership for a cheaper price.
Nature Made Vitamin D3
Why we chose it
Nature Made is 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.
Unlike Kirkland Signature, this product is available in most brick-and-mortar stores. You can pick your supplement up membership-free while out running errands. You can find it at grocery stores and pharmacies nationwide including Target, Walgreens, and Safeway.
Points to consider
Nature Made also only 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 does mean you can easily take more or less vitamin D as needed.
How we chose the best vitamin D supplement
Vitamin D3 is better than vitamin D2
In our search for the best vitamin D supplement, we learned that there are actually two types of vitamin D: D2 (ergocalciferol), which comes from plants, and D3 (cholecalciferol), which is manufactured using fish oil or — more commonly — lanolin taken from sheep wool and subjected to ultraviolet (UV) radiation. UV radiation is what our bodies use to make natural vitamin D when our skin is exposed to sunlight. Most people should choose a supplement with vitamin D3, since it’s absorbed more easily than D2.
“D3 mimics the way our bodies make vitamin D from sunlight and it’s more easily absorbed, making it the best option for most people.”
Because vitamin D3 is more widely recommended and more available in stores, we cut any supplements that use D2.
The Food and Drug Administration (FDA) regulates food products, but not dietary supplements. So it’s anybody’s guess if what’s in a pill actually matches what’s on its bottle label. Product ingredients can vary widely, and some supplements even contain harmful lead or other contaminants. In fact, Labdoor, a reputable third-party testing company, found that the actual dosage of vitamin D supplements sometimes exceeded what was listed on the label by as much as 900 percent. That’s why we required all of our top picks to be vetted by at least one of three reputable, independent labs:
United States Pharmacopeial Convention (USP) – A scientific non-profit that sets standards for quality and purity in medicines and food supplements in the US and more than 140 other countries.
Labdoor – A free consumer resource that focuses on testing dietary supplements for purity, accuracy, and value.
National Sanitation Foundation (NSF) – An independent organization that sets worldwide standards for consumer product safety.
Ever wonder why vitamin D, like many supplements, contains glycerin, water, cellulose, or other fillers? We did too, so we asked Jamie Shuck, brand manager for Vitabiotics, one of the UK’s largest vitamin manufacturers. “Vitamin D is needed by the body only in tiny microgram amounts, which is barely a speck in its pure form — far smaller than a grain of rice and too small to even pick up,” Shuck explained. “Therefore, all vitamin D supplements must be formulated with other ingredients to increase the volume of the product, so customers are able to measure a safe and accurate dose.”
While it’s impossible to find a vitamin D supplement that contains just vitamin D, we did look for products that avoided questionable additives like sugar, flavoring, artificial color, and preservatives. We also chose products containing vitamin D with no other dietary supplements. According to the experts we talked to, almost everyone needs a vitamin D supplement, while only some of us need or want additional ingredients like calcium or CoQ10. Products with proprietary blends make it hard to know the specific dose of vitamin D, which as Dr Feuerstein pointed out, “makes it difficult to treat someone who has a vitamin D deficiency,” so we cut those too.
Like vitamins A, E, and K, vitamin D is fat-soluble, which means it dissolves in fat rather than water. That means vitamin D is best absorbed by the body when taken with fatty foods and is the reason many vitamin D supplements also contain an oil.
If you choose a supplement that doesn’t include oil, nutritionist Shereen Lehman recommends taking it with a little added fat. “You don’t need a lot,” she explains. “A salad with dressing, or a little cheese, avocado, or meat are good. Even seafood would have enough natural fat to help with vitamin D absorption.”
But we wanted to make it easy, so we cut any supplements that didn’t include some form of oil or fatty acid from olives, soybeans, or another healthy source.
Guide to Vitamin D Supplements
How to make sure you’re getting enough vitamin D
Deficiency is common
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. Shuck adds, “Vitamin D also has other key functions in the body, such as helping to maintain normal immune system functioning.”
Get vitamin D in your diet
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.”
|Swordfish (3 oz)|
|Sockeye salmon (3 oz)|
|Canned tuna fish (3 oz)|
|Orange juice - vitamin D-fortified (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.
Some medical researchers, like Dr. Michael Holick, recommend getting 15 minutes of unprotected sunlight per day — in the middle of the day when the sun is brightest. And Dr. Andrew 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.