What Is the Best Calcium and Vitamin D Supplement?
The best calcium and vitamin D supplement for most people is Nature Made Calcium 600 mg with D3: it is on the USP Verified list, and one tablet gives 600 mg of calcium and 400 IU of vitamin D3 for $0.07. Want calcium citrate, which you can take without food? 21st Century Calcium Citrate + D3 Petites has the same amounts as Citracal’s Petites. We checked 37.
By Erin Rose Updated November 2026 How we score
1. Our pick, on the USP Verified list
- Calcium
- 600 mg a tabletCalcium carbonate; take with a meal
- Vitamin D3
- 400 IU a tablet800 IU at 2 tablets
- Testing
- USP VerifiedListed under this name
- Cost
- $0.13 a dayAt 2 tablets; $14.36 for 220
Why we pick it Nature Made Calcium 600 mg with D3 is on the USP Verified list under this exact name, and ChatGPT names Nature Made in 16 of its 19 saved answers to this question and its D3, women and osteoporosis versions. Kirkland’s citrate costs $0.06 less a day at each label’s most and is USP Verified too. At that dose Nature Made gives 1,200 mg of calcium to Kirkland’s 500 mg, and it costs $0.07 per 600 mg of calcium to Kirkland’s $0.09.
Which one should you buy?
2. 21st Century Calcium Citrate + D3 Petites: calcium citrate in a small tablet
Two tablets give 400 mg of calcium citrate and 500 IU of vitamin D3, the same amounts as Citracal’s Petites. Citracal is the brand ChatGPT names first in 13 of its 19 saved answers to this question and its D3, women and osteoporosis versions. NIH says citrate can be taken without food. The label says 2 tablets twice a day: 4 give 800 mg and 1,000 IU.
21st Century Calcium Citrate + D3 Petites
$0.22 a day at 4 tablets · $10.99 for 200
3. Kirkland Signature Calcium Citrate, Magnesium and Zinc: USP Verified, with magnesium and zinc
Two tablets give 500 mg of calcium citrate, 800 IU of vitamin D3, 80 mg of magnesium and 10 mg of zinc. Taken at the most each label says, it has the lowest cost a day of the 9 here. As citrate, it needs no food.
Kirkland Signature Calcium Citrate, Magnesium and Zinc
$0.08 a day at 2 tablets · $18.85 for 500
4. Citracal Slow Release 1200: one dose a day
The label says 2 caplets once a day, in the morning with food. They give 1,200 mg of calcium (carbonate and citrate), 1,000 IU of vitamin D3 and 80 mg of magnesium.
Citracal Slow Release 1200
$0.23 a day at 2 caplets · $21.46 for 185
Choose Nature Made for a USP Verified tablet at $0.07 for 600 mg, 21st Century Petites for a small citrate tablet you can take without food, Kirkland for magnesium and zinc in the same 2 tablets, and Citracal Slow Release for one dose a day.
ChatGPT names Citracal, Nature Made and Kirkland in most of its answers
In its 19 saved answers to this question and its D3, women and osteoporosis versions, ChatGPT names Citracal in 17, Nature Made in 16 and Kirkland in 11. Citracal comes first in 13 and Nature Made in 3. New Chapter, Solgar, Thorne and Caltrate come up once or twice each.
Its tips: citrate if you take acid reflux medicine, 500 to 600 mg of calcium at a time, 800 to 1,000 IU of vitamin D3, and a USP or NSF mark on the bottle.
Seven of 37 are on a testing list under their own name; 12 use calcium citrate and 11 use carbonate
We checked 37 calcium supplements with vitamin D sold on Amazon and read each one’s amounts and directions from its label photos or listing. Seven are on a third-party testing list under their own name: Nature Made, Kirkland’s citrate, Vitafusion and Kirkland’s gummies on the USP (U.S. Pharmacopeia) Verified list, and NATURELO, Caltrate Gummy Bites and Theralogix TheraCal D4000 on the NSF International NSF/ANSI 173 list.
Of the 37, 12 use calcium citrate, 11 calcium carbonate and 1 both (Citracal Slow Release); 7 are gummies made with calcium phosphate, and 6 use calcium from algae, hydroxyapatite or malate. At the most each label says to take in a day, vitamin D runs from 125 IU (Bariatric Advantage 250 mg chews) to 4,000 IU (Theralogix and Alive! gummies).
Here are the 9 with a buy button, our pick first. The first group is on a testing list; the second is not on a testing list under its own name. After our pick, each group runs from lowest cost a day.
| Supplement | A day | Cost a day | Buy |
|---|---|---|---|
| On a testing list | |||
 Nature Made Calcium 600 mg with D3Our pick220 tabletsOn USP Verified | 2 tablets: 1,200 mg calcium (carbonate), 800 IU vitamin D | $0.13 | See on Amazon |
| Kirkland Signature Calcium Citrate, Magnesium and Zinc500 tabletsOn USP VerifiedAdds 80 mg magnesium and 10 mg zinc | 2 tablets: 500 mg calcium (citrate), 800 IU vitamin D | $0.08 | See on Amazon |
 Vitafusion Calcium Gummies100 gummiesOn USP Verified | 2 gummies: 500 mg calcium (phosphate), 1,000 IU vitamin D | $0.24 | See on Amazon |
 NATURELO Bone Strength120 capsulesOn NSF/ANSI 173Plant calcium from algae | 4 capsules: 600 mg calcium (from algae), 1,000 IU vitamin D | $0.93 | See on Amazon |
 Caltrate Gummy Bites 600+D350 gummy bitesOn NSF/ANSI 173 | 4 gummy bites: 1,000 mg calcium (phosphate), 1,600 IU vitamin D | $1.16 | See on Amazon |
| Citrate, slow release and plant calcium, not on a testing list under their own name | |||
| 21st Century Calcium Citrate + D3 Petites200 small tablets | 4 tablets: 800 mg calcium (citrate), 1,000 IU vitamin D | $0.22 | See on Amazon |
| Citracal Slow Release 1200185 capletsOne dose a day; adds 80 mg magnesium | 2 caplets: 1,200 mg calcium (carbonate and citrate), 1,000 IU vitamin D | $0.23 | See on Amazon |
 BariMelts Calcium Citrate120 dissolving tabletsMelts in the mouth | 2 tablets: 500 mg calcium (citrate), 1,500 IU vitamin D | $0.46 | See on Amazon |
 New Chapter Bone Strength Take Care120 slim tabletsPlant calcium from algae; adds vitamin K2 | 3 tablets: 905 mg calcium (from algae), 1,000 IU vitamin D | $0.81 | See on Amazon |
Take one tablet with each of two meals, and count the calcium in your food
NIH says the share of calcium the body absorbs goes down as the amount taken at one time goes up, so split two tablets between two meals. Adults 19 to 50 and men 51 to 70 need 1,000 mg of calcium a day from food and supplements together; women 51 to 70 and everyone over 70 need 1,200 mg. Count your food first; one or two tablets fill the rest. More in our calcium dosage guide.
NIH puts the adult upper limit for calcium at 2,000 to 2,500 mg a day, food and supplements together.
Vitamin D helps you absorb calcium: 600 IU a day to age 70, 800 IU after
NIH says vitamin D helps the gut absorb calcium. It sets the daily amount at 600 IU for ages 1 to 70 and 800 IU over 70, and the upper limit for adults at 4,000 IU a day. Two Nature Made tablets give 800 IU.
Nature Made’s label: 600 mg of calcium and 400 IU of vitamin D3 in each tablet
The Nature Made Calcium 600 mg with D3 label
Questions people ask
How many Nature Made Calcium 600 mg with D3 tablets should I take a day?
One or two. The label says adults take 1 tablet 1 to 2 times a day with water and a meal. Two tablets give 1,200 mg of calcium and 800 IU of vitamin D3.
Is calcium citrate or calcium carbonate better?
Both work. NIH says citrate can be taken without food, and that calcium is absorbed better with food in general. Nature Made is carbonate, so its label says to take it with a meal. More in citrate vs carbonate.
Is there a smaller calcium pill with vitamin D?
Yes. 21st Century Calcium Citrate + D3 Petites are small tablets, about half an inch long in the brand’s photo, with 200 mg of calcium citrate each.
How we picked
On November 9, 2026 we read the label of each of the 37 and searched five testing lists for each: NSF/ANSI 173, NSF Certified for Sport, Informed Choice, Informed Sport and USP Verified. Prices are Amazon’s, read November 9, 2026.
The other 28 we checked: Theralogix TheraCal D4000; Kirkland Signature Calcium Adult Gummies; Nature Made softgels and gummies; Nature’s Bounty softgels, tablets and gummies; Citracal Petites (400 mg of calcium citrate and 500 IU of D3 in 2 caplets), Citracal Maximum Plus (650 mg and 1,000 IU in 2 caplets) and Citracal Calcium Gummies; Caltrate 600+D3 tablets, Minis, Soft Chews and Chewables; Viactiv soft chews; Alive! gummies; Equate tablets and soft chews; Solgar, NOW and Life Extension calcium citrate; PlantFusion and Garden of Life plant calcium; Country Life Triple Action Bone Solid; Thorne Advanced Bone Support; Bariatric Fusion soft chews; and Bariatric Advantage chewy bites in 500 mg and 250 mg.
Sources
- Amazon listings and label photos of the 37 supplements, prices read November 9, 2026.
- Testing lists, read November 9, 2026: NSF/ANSI 173 list; NSF Certified for Sport; Informed Choice; Informed Sport; USP Verified.
- NIH Office of Dietary Supplements fact sheets for health professionals, read November 9, 2026: Calcium, Vitamin D.