Where it sits in the atlas: Nature Made markets this tablet for bone health, which is why it sits under Skin, hair & bone. That is the seller's positioning, not our finding. The entry checks the label amounts, the absorption rules for calcium carbonate, and the medication cautions against that positioning.
The short version
- One tablet supplies 600 mg of calcium as calcium carbonate (46% of the Daily Value) and 10 mcg, or 400 IU, of vitamin D3 (50%). The label says one tablet, one to two times a day, with water and a meal.
- The nutrition sources we opened say calcium carbonate is absorbed best with food and in amounts of about 500 mg at a time, so the label's one-tablet-per-meal pattern is the right one; two tablets swallowed together is not.
- The 220-tablet bottle was $16.27 on Amazon on September 30, 2026, listed as in stock and sold by Amazon.com, about 7 cents per tablet.
What the label shows
We read the Supplement Facts panel from the back-label image on Nature Made's own product page and cross-checked it against the ingredient and directions text on the Amazon listing for the 220-count bottle, both on September 30, 2026. The serving size is one tablet.
| Ingredient | Amount per serving | What to know |
|---|---|---|
| Calcium (as calcium carbonate) | 600 mg · 46% DV | The panel figure is elemental calcium, the part the body can use, measured against the FDA Daily Value of 1,300 mg [7]. Calcium carbonate needs stomach acid to dissolve, which is why the label pairs it with a meal [3] [6]. |
| Vitamin D3 (as cholecalciferol) | 10 mcg (400 IU) · 50% DV | Measured against the FDA Daily Value of 20 mcg [7]. Vitamin D helps the body absorb and hold on to calcium [4]. 400 IU is two-thirds of the 600 IU adult RDA and half of the 800 IU recommended past age 70. |
| Other ingredients | — | Cellulose gel, hypromellose, maltodextrin, croscarmellose sodium, polyethylene glycol, magnesium stearate, per the back-label image on naturemade.com. The Amazon listing's ingredient text for the 220-count also lists gelatin and corn starch; if you avoid gelatin, read the bottle you receive rather than either web page. |
The label's checkmarks read gluten free, no color added and no artificial flavors. Directions: "Adults, take 1 tablet 1 to 2 times daily with water and a meal," with a caution to consult a physician if you take any medication. The bottle carries the USP Verified mark, Nature Made's page says USP tested the ingredients, strength and manufacturing process, and the Amazon listing's first bullet says the same. USP's own public directory at quality-supplements.org refused our connection, so we credit the mark on the label and brand page alone; USP verification covers identity, strength and contaminants, not whether a product does anything. The back label reads "Distributed by Nature Made Nutritional Products, West Hills, CA"; Amazon lists the manufacturer as Pharmavite LLC. The back label also carries a standard FDA-authorized statement about lifelong calcium and vitamin D intake from a well-balanced diet; it concerns the whole diet over a lifetime, not this tablet, and we do not repeat or evaluate it here.
What the evidence shows
Calcium. Two independent references give the same adult targets: 1,000 mg a day for adults aged 19 to 50 and for men to 70, and 1,200 mg for women from 51 and everyone from 71 [3] [5]. The upper intake level, food and supplements combined, is 2,500 mg a day to age 50 and 2,000 mg after that [3] [5]. Two tablets add 1,200 mg before any food is counted, so the label's upper dose is a full day's target by itself; one tablet is the more common fit for a diet that already covers part of the need. Nature Made's page cites a figure that 43% of American adults get less calcium from food than the estimated average requirement; that is the brand's citation, unchecked by us [1].
Absorption. Both references say calcium carbonate should be taken with food, because it needs stomach acid to dissolve, and that absorption is best when no more than about 500 mg of elemental calcium is taken at once [3] [5]. A 600 mg tablet is already past that line, so two together is the one thing the label does not forbid but the science argues against. Calcium citrate needs no stomach acid and can be taken without food [3], which matters for people on acid-reducing medicine.
Vitamin D3. The adult RDA is 600 IU (15 mcg) to age 70 and 800 IU (20 mcg) from 71, with an upper level of 4,000 IU (100 mcg) a day [4]. Two tablets give 800 IU; add any multivitamin or stand-alone vitamin D to that figure, because the limit applies to the total. In comparisons of the two forms, D3 tended to raise blood levels more, and hold them longer, than D2 [4].
Safety questions. Two questions follow calcium tablets around, and the evidence on both is mixed. On kidney stones, one large randomized trial of 1,000 mg of calcium plus 400 IU of vitamin D a day reported more self-reported stones, while a later systematic review found no effect [5]; Harvard adds that calcium from food appears protective even where calcium in pill form has been linked to more stones [3]. On the heart, the most recent meta-analysis of 18 randomized trials found no sign of extra heart problems or higher mortality with calcium supplements [5], though Harvard notes some research raising the possibility of calcium building up in blood vessels with long-term high doses in certain people [3]. The safe reading is not to take more than you need.
Calcium binds several medicines in the gut and blocks their absorption: tetracycline and quinolone antibiotics, bisphosphonate bone medicines, levothyroxine, thiazide diuretics and digoxin. The Linus Pauling Institute's rule is to take the medicine two hours before, or four to six hours after, the calcium [5]; MedlinePlus puts it as not taking calcium carbonate within one to two hours of any other medicine [6]. Nature Made's own page adds blood pressure medicines, warfarin-type blood thinners and NSAIDs to its "use caution with" list [1]. If you take any of these, ask a pharmacist how to space the doses.
How it fits a daily routine
One tablet with a meal; a second, if you take one, with a different meal hours later. Calcium carbonate can cause constipation, belching or an upset stomach in some people [6], so start with one a day for a week before adding the second. Within this atlas's Skin, hair & bone group the collagen powder contains no calcium, so there is no overlap; a multivitamin or a stand-alone vitamin D product overlaps on the D3 line and should be counted. Keep any medicine on the interaction list at least two hours away from the tablet.
Price and where it is sold
On September 30, 2026 the 220-tablet bottle was $16.27 on Amazon, in stock and sold by Amazon.com; Amazon showed $0.07 per tablet, and our own division gives 7.4 cents. That is a little over seven months at one tablet a day, or 110 days, about 15 cents a day, at two. The same page offers 60- and 120-count variations of the identical tablet. The listing was marked non-returnable for food-safety reasons, so Amazon's usual return window for most items may not apply; read the return line before ordering. For context, Nature Made's own product page marked this item as discontinued in its online store when we rechecked on September 30, 2026, so Amazon may be carrying remaining stock; check that the bottle and panel you receive match what is described here. Prices move; every figure here is a snapshot of that date.
Who should look elsewhere
- Anyone who takes a medicine on the interaction list above, or any prescription medicine, should ask a pharmacist or clinician first; the label carries the same caution.
- People with a history of kidney stones, or who have been told their blood calcium runs high, should not add a calcium tablet without a clinician's say-so.
- People who take acid-reducing medicine may absorb calcium carbonate poorly; a calcium citrate product is the usual alternative.
- Anyone already taking a multivitamin with calcium and vitamin D, or a separate vitamin D product, should add up the totals first; it is easy to pass the calcium upper limit without noticing.
- Anyone who is pregnant or nursing should ask a clinician before starting any supplement.
Sources
- Nature Made (Pharmavite LLC). Product page for Calcium 600 mg with Vitamin D3 Tablets, with the back-label image, suggested use, USP statement and the brand's interaction cautions. View the product page
- Amazon listing for the 220-tablet bottle (ASIN B002FH5I0I), checked for title, count, ingredient text, directions, price and stock on September 30, 2026. Linked from the fact sheet on this page.
- Harvard T.H. Chan School of Public Health, The Nutrition Source. Overview of calcium: adult RDAs and upper limits, carbonate versus citrate, the 500 mg-at-a-time note, and the mixed findings on kidney stones and the heart. Read the overview
- Harvard T.H. Chan School of Public Health, The Nutrition Source. Overview of vitamin D: adult RDAs, the 4,000 IU upper limit, vitamin D's role in calcium absorption, and D3 compared with D2. Read the overview
- Linus Pauling Institute, Oregon State University. Micronutrient Information Center article on calcium: RDAs, upper limits, dosing for absorption, drug interactions and dose spacing, and the trial and meta-analysis evidence on kidney stones and cardiovascular events. Read the article
- MedlinePlus (U.S. National Library of Medicine). Drug information for calcium carbonate: take with food, keep one to two hours away from other medicines, and common side effects. Read the entry
- U.S. Food and Drug Administration. Daily Value reference table for the Nutrition and Supplement Facts labels (calcium 1,300 mg; vitamin D 20 mcg). See the table
This entry is educational and is not medical advice. Ask a qualified clinician before starting any supplement, especially if you are pregnant, nursing, or take medication.