Label arithmetic · NIH DSLD 210415
NOW Magnesium & Calcium: 267 mg of magnesium per tablet – citrate + glycinate + oxide
800 mg of magnesium per serving. From citrate + glycinate + oxide; no US price matched (Nov 2). Inside: label lines, ingredients.
NOW Magnesium & Calcium declares 800 mg of elemental magnesium per 3 tablet(s); the magnesium salt is not resolved from the filed record, Single-salt capacity audit excluded as of 2026-10-17: one salt with a defined elemental fraction is not resolved., as of 2026-11-02. No US retail price matched as of 2026-11-02. NIH DSLD 210415, label dated 2019-12-22.
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: 190% vs 190%
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.
How much magnesium compound is pressed into one tablet?
The compound mass behind this label cannot be computed as of 2026-11-02: Single-salt capacity audit excluded as of 2026-10-17: one salt with a defined elemental fraction is not resolved.. The filed amounts are listed in the next block.
computed with assumption| Measure | Value |
|---|---|
| Elemental magnesium per serving | 800 mg |
| Units per serving | 3 |
| Magnesium salt per serving | Not computable as of 2026-11-02 |
| Magnesium salt per tablet | 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 210415 · label 2019-12-22; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
How much elemental magnesium is actually in this label's filed magnesium lines?
NOW Magnesium & Calcium files 1 magnesium line in NIH DSLD 210415; the selected primary line declares 800 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 |
|---|---|---|
| 800 mg | citrate, glycinate, oxide · Magnesium (Form: from Magnesium Oxide, Magnesium Glycinate, Magnesium Taurinate, Magnesium Citrate, and Aquamin TG seaweed derived Minerals) | Primary serving |
Source · NIH DSLD 210415 · label 2019-12-22; 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 3 magnesium forms (citrate, glycinate, 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 glycinate | 11.8–14.1% | named on label |
| Magnesium oxide | 60.3% | named on label |
Source · NIH DSLD 210415 · label 2019-12-22; 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?
Days per bottle cannot be computed for NOW Magnesium & Calcium as of 2026-11-02: the filed directions give no complete daily frequency.
computed| Measure | Value |
|---|---|
| Net contents as filed | 100 Tablet(s) |
| Serving size as filed | 3 Tablet(s) |
| Servings per container | 33 |
| Servings per day in the directions | Not filed as of 2026-11-02 |
| Days per bottle | Not computable as of 2026-11-02 |
| $ 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 210415 · label 2019-12-22; snapshot 2026-08-10 · release 2026-08-10-f441aa9f · CSV · method
What does "190% Daily Value" mean here, and does it recompute?
The label declares 190% Daily Value; 800 mg against the 420 mg reference in 21 CFR 101.9 recomputes to 190%, the same within one point.
computed| Group as filed | Declared | Reference | Recomputed |
|---|---|---|---|
| Adults and children 4 or more years of age | 190% | 420 mg | 190% |
Source · NIH DSLD 210415; 21 CFR 101.9 · label 2019-12-22 · release 2026-08-10-f441aa9f · CSV · method
Why does this label contain magnesium stearate, what shell is it, and who is it filed for?
NOW Magnesium & Calcium files 7 other ingredients, including magnesium stearate (reference fraction 4.1% magnesium; no quantity filed, so it is not added to the total) and a vegetarian shell.
measured| Entry | Filed ingredient or declaration |
|---|---|
| 1 | Microcrystalline Cellulose |
| 2 | Maltodextrin |
| 3 | Croscarmellose Sodium |
| 4 | Stearic Acid |
| 5 | Vegetarian Coating |
| 6 | Magnesium Stearate |
| 7 | Silicon Dioxide |
| Shell | vegetarian |
4 additional rows
| Entry | Filed ingredient or declaration |
|---|---|
| Target group | Adult (18 - 50 Years) |
| Target group | Kosher |
| Target group | Gluten Free |
| Target group | Dairy Free |
Source · NIH DSLD 210415 · label 2019-12-22; 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?
NOW has 12 FDA recall records matched by brand name in the enforcement data queried 2026-10-19. NOW 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-1726-2013 | 2013-07-31 | It has been determined that this product contains an undeclared ingredient, licorice extract, which contains glycyrrhizin derived from licorice root. | Terminated |
| F-0770-2014 | 2013-12-25 | Firm is recalling dietary supplements containing a raw material which may contain >0.3 ppb chloramphenicol | Terminated |
| F-1537-2014 | 2014-02-26 | Digestive enzyme capsules manufactured by NOW Foods may contain the antibiotic chloramphenicol. | Terminated |
| F-1484-2017 | 2017-02-22 | Product's supplement fact panel incorrectly states that the product contains 75 mg (milligrams) of Molybdenum, when it actually contains 75 mcg (micrograms). | Terminated |
| F-0682-2019 | 2018-12-12 | NOW Health Group Inc. initiated a voluntary recall of NOW s Vitamin B-50 mg 100 Veg Caps product code 0420 because it is mislabeled as Vitamin B-50 mg 100 Veg Caps. | 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 210415 · label 2019-12-22; 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 210415 · label 2019-12-22; 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 210415 (label 2019-12-22, 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: one salt with a defined elemental fraction is not resolved.; No US retail price matched as of 2026-11-02 (barcode 7 33739 01277 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 210415 |
| Label date | 2019-12-22 |
| Date entered into DSLD | 2019-12-22 |
| Barcode (UPC) as filed | 7 33739 01277 7 |
| Label version · Image difference, same product | NIH DSLD 14545 |
| Label version · Image difference, same product | NIH DSLD 51707 |
| Label version · Image difference, same product | NIH DSLD 56828 |
| Label version · Image difference, same product | NIH DSLD 70554 |
32 additional rows
| Field | As filed |
|---|---|
| Label version · Image difference, same product | NIH DSLD 77543 |
| Label version · Package size difference, same product | NIH DSLD 14545 |
| Label version · Package size difference, same product | NIH DSLD 51707 |
| Label version · Package size difference, same product | NIH DSLD 56828 |
| Label version · Package size difference, same product | NIH DSLD 70554 |
| Label version · Package size difference, same product | NIH DSLD 77543 |
| Label version · Package size difference, same product | NIH DSLD 210416 |
| Manufactured & quality tested by | NOW Foods, Bloomingdale, IL, USA |
| Claim category as filed | Nutrient |
| Claim category as filed | All Other |
| Claim category as filed | Structure/Function |
| Storage | Suggested Usage: Take 3 tablets daily, preferably in divided doses, with food or at bedtime. |
| Formula re: Contains | The reverse ratio formula is formulated to provide higher levels of magnesium for those who desire the nerve, muscle and bone supporting effects of this essential mineral. Zinc and vitamin D-3 are included in this product for their roles in bone metabolism. |
| 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. |
| Precautions re: All Other | Caution: For adults only. |
| Precautions re: Pregnant or Nursing or Prescription Medications | Consult physician if pregnant/nursing, taking medication, or have a medical condition. |
| Precautions re: Children | Keep out of reach of children. |
| Formulation re: Other | Natural color variation may occur in this product. |
| Storage | Store in a cool, dry place after opening. |
| Brand IP Statement(s) re: (c), (TM), (SM) | L-OpticZinc is a registered trademark of InterHealth Nutraceuticals Inc. Aquamin is a registered trademark of Marigot Limited. |
| Formulation re: Other | Nerve and bone support |
| Formula re: Contains | Reverse 2:1 ratio With Zinc and Vitamin D-3 |
| Formulation re: Does NOT Contain | Non-GMO |
| FDA Statement of Identity | A Dietary Supplement |
| Seals/Symbols | Triangle K |
| Formula re: Kosher | Triangle K |
| General Statements: All Other Content | Minerals Family owned since 1968. |
| Formulation re: Does NOT Contain | Not manufactured with wheat, gluten, soy, milk, egg, fish or shellfish ingredients. |
| Precautions re: Allergies | Not manufactured with wheat, gluten, soy, milk, egg, fish or shellfish ingredients. Produced in a GMP facility that processes other ingredients containing these allergens. |
| Seals/Symbols | GMP Quality Assured |
| Physical state | Tablet or Pill |
| Registry snapshot | 2026-08-10 |
Source · NIH DSLD 210415 · label 2019-12-22; 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.