Label arithmetic · NIH DSLD 214326
Source Naturals Coral Calcium/Magnesium 2:1 Ratio: 100 mg of magnesium per capsule, 3 capsules a day – citrate + oxide
100 mg of magnesium per capsule; the label's 3 capsules a day give 300 mg. From citrate + oxide. Inside: label lines, ingredients.
Source Naturals Coral Calcium/Magnesium 2:1 Ratio declares 300 mg of elemental magnesium per 3 capsule(s); the magnesium salt is not resolved from the filed record, Single-salt capacity audit excluded as of 2026-10-17: buffered, complex, blend or asporotate wording leaves the composition unresolved., as of 2026-11-02. No US retail price matched as of 2026-11-02. NIH DSLD 214326, label dated 2020-02-26.
as filedData release 2026-08-10-f441aa9f · registry snapshot 2026-08-10 · latest price observation 2026-10-19 · chemistry 2026-10-17
Mass: not computable · Price: none matched · % DV: 75% vs 71%
Elemental: The magnesium itself; the rest of the compound weight is the partner molecule.
Compound: The whole salt, such as magnesium glycinate, that must physically fit in the capsule.
Size 000: The largest standard capsule, about 1,100 mg of powder at 0.8 g/mL, the top of the usual 0.6–0.8 range; size 00 holds about 730 mg and size 0 about 545 mg.
Recompute with your price
Enter the price you paid; the declared amount and servings of this label are prefilled, so the result is the cost per 100 mg of elemental magnesium for your bottle.
Same-salt comparison appears here.
Will 300 mg of magnesium actually fit in one capsule, or do I need more than one?
The compound mass behind this label cannot be computed as of 2026-11-02: Single-salt capacity audit excluded as of 2026-10-17: buffered, complex, blend or asporotate wording leaves the composition unresolved.. The filed amounts are listed in the next block. Lower bound, not a measurement: even if all 300 mg of magnesium per serving came from magnesium oxide (60.3% magnesium), the richest magnesium salt used in supplements, because the complex or buffer does not specify every carrier, each of the 3 capsules would need at least 166 mg of compound, so at this bound it needs at least a size 0 capsule (about 545 mg at 0.8 g/mL); the actual form, which the label does not name, may need more.
computed with assumption| Measure | Value |
|---|---|
| Elemental magnesium per serving | 300 mg |
| Units per serving | 3 |
| Magnesium salt per serving | Not computable as of 2026-11-02 |
| Magnesium salt per capsule | Not computable as of 2026-11-02 |
| Capsule capacity 0 · 00 · 000 | 545 · 730 · 1,100 mg |
| Verdict | Not computable as of 2026-11-02 |
Source · NIH DSLD 214326 · label 2020-02-26; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
How much elemental magnesium is actually in this label's filed magnesium lines?
Source Naturals Coral Calcium/Magnesium 2:1 Ratio files 1 magnesium line in NIH DSLD 214326; the selected primary line declares 300 mg of elemental magnesium per serving, against 0 other rows excluded from the primary amount. A salt named under another nutrient does not turn that nutrient's quantity into elemental magnesium.
measured| Filed amount | Salt or note as filed | Role |
|---|---|---|
| 300 mg | citrate, oxide · Magnesium (Form: as Magnesium Oxide, Amino Acid complex, and Magnesium Citrate) | Primary serving |
Source · NIH DSLD 214326 · label 2020-02-26; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Does this label's magnesium claim hold up, or could the magnesium come from another source?
The label names 2 magnesium forms (citrate, oxide); a named blend does not establish how much magnesium each form contributes, so the resolved reading is the most favourable one, compared with oxide, the salt richest in magnesium at 60.3%.
computed with assumption| Form named on the label | Elemental fraction | Source |
|---|---|---|
| Magnesium citrate | 11.3–16.2% | named on label |
| Magnesium oxide | 60.3% | named on label |
Source · NIH DSLD 214326 · label 2020-02-26; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Is this a good price for the elemental magnesium I'm actually getting?
No US retail price is matched to this label as of 2026-11-02, and without a resolved salt there is no same-salt comparison.
computed| Rank | Label | Per 100 mg | Observed |
|---|
Source · Amazon via licensed data provider; NIH DSLD · unique ASIN × date; prices observed 2026-10-26 to 2026-11-02 · release 2026-08-10-f441aa9f · CSV · method
How many days will this bottle last at the label's own serving, and what does a day cost?
At the label's own serving, Source Naturals Coral Calcium/Magnesium 2:1 Ratio lasts 60 days: 60 servings against 1 serving a day in the filed directions.
computed| Measure | Value |
|---|---|
| Net contents as filed | 180 Capsule(s) |
| Serving size as filed | 3 Capsule(s) |
| Servings per container | 60 |
| Servings per day in the directions | 1 |
| Days per bottle | 60 days |
| $ per 30 days at one label serving a day | No ranked price as of 2026-11-02 |
| $ per 30 days at 420 mg Daily Value | No ranked price as of 2026-11-02 |
Source · NIH DSLD 214326 · label 2020-02-26; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What does "75% Daily Value" mean here, and does it recompute?
The label declares 75% Daily Value; 300 mg against the 420 mg reference in 21 CFR 101.9 recomputes to 71%, a difference of 4 points. Labels filed under the earlier 400 mg reference, or with a different filing basis, show gaps of this kind.
computed
Chart data
| Displayed chart text |
|---|
| Declared vs recomputed % |
| DV |
| 71 · 75 |
| Declared vs |
| recomputed % DV |
| Group as filed | Declared | Reference | Recomputed |
|---|---|---|---|
| Adults and children 4 or more years of age | 75% | 420 mg | 71% |
Source · NIH DSLD 214326; 21 CFR 101.9 · label 2020-02-26 · release 2026-08-10-f441aa9f · CSV · method
Why does this label contain magnesium stearate, what shell is it, and who is it filed for?
Source Naturals Coral Calcium/Magnesium 2:1 Ratio files 4 other ingredients, including magnesium stearate (reference fraction 4.1% magnesium; no quantity filed, so it is not added to the total) and a gelatin shell.
measured| Entry | Filed ingredient or declaration |
|---|---|
| 1 | Gelatin |
| 2 | Microcrystalline Cellulose |
| 3 | Silica |
| 4 | Magnesium Stearate |
| Shell | gelatin |
| Target group | Adult (18 - 50 Years) |
| Target group | Gluten Free |
| Target group | Dairy Free |
Source · NIH DSLD 214326 · label 2020-02-26; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What has research measured about this form, and about side effects?
No study in the registry measured an unresolved salt as of 2026-11-02.
measured| Year | Study | PubMed |
|---|
Source · PubMed-checked study registry · registry checked 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Has this brand had FDA recalls or adverse event reports?
Source Naturals has 6 FDA recall records matched by brand name in the enforcement data queried 2026-10-19. Source Naturals has FDA CAERS adverse event reports on record at brand level, as do 143 of 273 brands in this registry; openFDA states that “there is no certainty that the reported event (adverse event) was actually due to the product” and that reports “cannot be used to estimate the incidence of these events.”
measured| Recall | Date | Reason | Status |
|---|---|---|---|
| F-0100-2014 | 2013-11-13 | The firm found small piece of metal fragment in one tablet during its inspection process. | Terminated |
| F-1100-2014 | 2013-12-25 | Dietary Supplements were made with bulk products provided by National Enzyme Company which are currently under recall for chloramphenicol | Terminated |
| F-2178-2017 | 2017-05-10 | Testing of Vitamin D-3 as a result of a consumer complaint found specific lots to have lower concentrations than product specifications of ingredient labeling. | Terminated |
| F-2380-2017 | 2017-07-19 | Dietary supplements contain low levels of undeclared boron | Terminated |
| F-2383-2017 | 2017-07-19 | Dietary supplements contain low levels of undeclared boron | Terminated |
Source · openFDA enforcement and CAERS · queried 2026-10-19 · release 2026-08-10-f441aa9f · CSV · method
Is this the same formula as another brand's, and how do their prices differ?
Same filed formulation as 1 other labels of this brand; no other brand files it as of 2026-11-02.
computed| Label | Brand | Price per 100 mg |
|---|---|---|
| No cross-brand match as of 2026-11-02 |
Source · NIH DSLD 214326 · label 2020-02-26; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Which labels are closest to this one, with the same salt and dose?
No other label files the same resolved salt within ±10% of this label's dose per unit as of 2026-11-02.
computed| Label | Elemental per unit | Price | Verdict |
|---|---|---|---|
| No neighbour as of 2026-11-02 |
Source · NIH DSLD 214326 · label 2020-02-26; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
Where does this record come from, what is missing, and how do I cite or correct it?
Every value on this page traces to NIH DSLD 214326 (label 2020-02-26, snapshot 2026-08-10) and the chemistry model of 2026-09-13. 3 gaps remain: Single-salt capacity audit excluded as of 2026-10-17: buffered, complex, blend or asporotate wording leaves the composition unresolved.; No US retail price matched as of 2026-11-02 (barcode 0 21078 01684 7); A single salt with a defined elemental fraction is unresolved as of 2026-11-02. The CSV carries the values shown here.
measured| Field | As filed |
|---|---|
| NIH DSLD label | NIH DSLD 214326 |
| Label date | 2020-02-26 |
| Date entered into DSLD | 2020-02-26 |
| Barcode (UPC) as filed | 0 21078 01684 7 |
| Label version · Package size difference, same product | NIH DSLD 214325 |
| Label version · Package size difference, same product | NIH DSLD 295688 |
| Manufactured for | Source Naturals, Inc., Santa Cruz, CA |
| Claim category as filed | Nutrient |
15 additional rows
| Field | As filed |
|---|---|
| Claim category as filed | All Other |
| Claim category as filed | Structure/Function |
| Formulation re: Other | Eco-friendly |
| FDA Statement of Identity | Dietary Supplement |
| Suggested/Recommended/Usage/Directions | Suggested Use: 3 capsules daily. |
| Precautions re: Pregnant or Nursing or Prescription Medications | Note: If you are pregnant, may become pregnant, or breastfeeding, consult your health care professional before using this product. |
| Storage | Store in a cool, dry place. |
| Formula re: Contains | Source Naturals Coral Calcium/Magnesium is an excellent source of these two alkaline minerals is an optimal 2:1 ratio. In addition to building healthy bones, calcium plays essential roles in muscle contractions, heartbeat, blood clotting, nerve transmission, and in converting signals from hormones in the blood into actions within cells. Magnesium is involved in over 300 vital cellular processes, and helps to regulate the action of calcium in muscle function and heart health. The vitamin D in this formula supports intestinal absorption of calcium and its optimal use in the body. |
| Formulation re: Other | Source Naturals Coral Calcium/Magnesium is eco-friendly: It is harvested from fossilized (dead) coral and is not harmful to living coral. |
| Precautions re: All Other | Do not use if either tamper-evident seal is broken or missing. |
| Precautions re: Children | Keep out of the reach of children. |
| Formulation re: Does NOT Contain | Contains no yeast, dairy, egg, gluten, soy or wheat. Contains no artificial color, flavor or fragrance. |
| FDA Disclaimer Statement | These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. |
| Physical state | Capsule |
| Registry snapshot | 2026-08-10 |
Source · NIH DSLD 214326 · label 2020-02-26; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
6 brand pages linked below contain magnesium labels from the NIH DSLD registry snapshot dated 2026-08-10.