Label arithmetic · NIH DSLD 336940

tnvitamins Magnesium Oxide 420 mg

tnvitamins Magnesium Oxide 420 mg declares 420 mg of elemental magnesium as oxide, which needs 696 mg of salt per unit — a size 00 capsule or larger; NIH DSLD 336940, label dated 2025-09-25, calculation 2026-09-13.

FDA recall records for tnvitamins: 2 · queried 2026-09-13; brand-string matches across products.

Mass budget · computed; capsule comparison · modelled

What the declared salt would weigh

tnvitamins Magnesium Oxide 420 mg declares 420 mg of elemental magnesium per serving in NIH DSLD 336940, requiring 696.29 mg of magnesium oxide under the salt model calculated 2026-09-13.

Elemental-to-compound conversion for NIH DSLD 336940
StepValueEvidence
Declared elemental magnesium420 mg per servingobserved · label 2025-09-25
Resolved saltMagnesium oxide · full-recordcomputed · name resolved from filed text
Reference formulaMgO; 40.3 g/molcomputed · chemical reference
Elemental fraction60.32% by masscomputed
Compound mass per serving696.29 mg = 420 mg ÷ elemental fractioncomputed
Compound mass per discrete unit696.29 mgcomputed

At powder density 0.6–0.8 g/mL, 696 mg of powder requires at least a size 00 capsule (a size 0 holds about 545 mg).

The verdict uses the most favourable reading for the product — the smallest compound mass the label allows. It excludes the shell and other ingredients; their unreported masses are not added as guesses.

Size 0 holds about 545 mg, size 00 about 730 mg, and size 000 about 1,100 mg at powder density 0.6–0.8 g/mL. These are model inputs, not measurements of this product's capsule. Read the mass-budget method.

Label facts and derived measurements

The numbers for this label

tnvitamins Magnesium Oxide 420 mg has 11 published fields below, traced to NIH DSLD 336940 and the 2026-08-10 registry snapshot, with calculations dated 2026-09-13.

Values published in this page's Product metadata
FieldValueEvidence tier
NIH DSLD identifier336940observed
Resolved saltMagnesium oxidecomputed
Source of the resolved saltfull-recordobserved
Elemental magnesium per serving (mg)420observed
Servings per container120observed
Elemental magnesium per container (mg)50400computed
Compound mass per discrete unit696.29 mgcomputed
Capsule fill verdictneeds-00modelled
Required standard capsule size00modelled
Label date2025-09-25observed
Retail match confidenceunmatchedcomputed

Observed means a value transcribed from a label or price observation. Computed means arithmetic or normalization of those inputs. Modelled means the result depends on a stated physical assumption, including capsule capacity. Evidence tiers and their limits.

Source transcription · observed

Magnesium lines as filed

tnvitamins Magnesium Oxide 420 mg retains 1 magnesium-related rows in NIH DSLD 336940, including 1 rows selected for the primary serving, from label 2025-09-25, examined 2026-09-13.

Filed amounts, salt names and serving order
Filed amountServing orderFiled salt / notesCalculation role
420 mg1Salt not identified in this row as of 2026-09-13

from

Selected primary serving

The elemental amount comes from the selected magnesium line. A salt named under another nutrient does not make that nutrient's quantity an elemental magnesium value. Distinct unresolved primary amounts remain ambiguous; they are not added together.

Package arithmetic · observed inputs, computed totals

What the package works out to

tnvitamins Magnesium Oxide 420 mg works out to 120 days per package at the label's own serving and filed frequency of 1 servings per day, according to label 2025-09-25, calculated 2026-09-13.

Arithmetic using the label's own serving, not intake advice
Net contents as filed120 Capsule(s)
Discrete units in the package120
Serving size as filed1 Capsule(s)
Units per serving1
Servings per package120
Daily servings in the label instructions1
Days per package at the label's own serving120 days

Days = filed servings per container ÷ filed servings per day. If the label gives a frequency range, the largest frequency gives the shortest duration. Cost per serving = observed item price ÷ filed servings; cost per label-day multiplies this by the filed frequency. This follows the label's own instructions; it is package arithmetic, not intake advice.

Benchmark · 14 observed prices in oxide

A same-salt reference for this package

At the median cost per 100 mg observed across 14 oxide labels ($0.0571), a package of this size (50,400 mg elemental in tnvitamins Magnesium Oxide 420 mg) would correspond to $28.75, using observations from 2026-08-10 to 2026-09-11, calculated 2026-09-13. This is a benchmark, not a retailer quote.

Same-salt benchmark working
Salt and number of observationsMagnesium oxide · n = 14
Median observed cost per 100 mg$0.0571
Filed elemental magnesium per package50,400 mg
Benchmark package equivalent$28.75 = median EC100 × package elemental mg ÷ 100
Evidence tierbenchmark · calculated 2026-09-13

The median is the middle sorted observation, or the average of the two middle observations for an even group. Each label contributes one observation. This value is neither an offer nor an estimate of a specific retailer's current price.

Percent daily value · observed and computed

The label's percent daily value, recomputed

tnvitamins Magnesium Oxide 420 mg files 1 magnesium percent-daily-value entries in NIH DSLD 336940; the check below applies the group-specific references in 21 CFR 101.9 to its 420 mg primary serving, calculated 2026-09-13.

Declared values and current-reference arithmetic
Group as filedDeclaredReferenceRecomputedDifference
Adults and children 4 or more years of age100%420 mg100%0 percentage points

Percent daily value = declared elemental mg ÷ the group's reference mg × 100, rounded to an integer. The adult and age-four-plus reference is 420 mg. Historical labels can use earlier references; a difference does not establish a filing error. Full-record entries may cover multiple serving sizes, so this table identifies the primary-serving basis explicitly. Group references and interpretation.

Composition · observed

Other ingredients in the filed record

tnvitamins Magnesium Oxide 420 mg lists 3 other ingredients in NIH DSLD 336940, label dated 2025-09-25, examined 2026-09-13.

Other ingredients as filed
EntryIngredient
1Microcrystalline Cellulose
2Magnesium Stearate
3Gelatin

Capsule material: gelatin. The material classification follows the filed ingredient names; it is not a test of the shell.

This label lists magnesium stearate, whose reference elemental fraction is 4.1% by mass. No stearate quantity is available in this record as of 2026-09-13, so its magnesium contribution cannot be quantified or added to the Supplement Facts magnesium total.

Label declarations · observed

Target groups as filed

tnvitamins Magnesium Oxide 420 mg has 4 target-group entries in NIH DSLD 336940, label dated 2025-09-25, examined 2026-09-13.

Manufacturer-filed target groups
EntryFiled group
1Adult (18 - 50 Years)
2No Allergies
3Gluten Free
4Dairy Free

Provenance · observed

Registry record, versions and scanned label

tnvitamins Magnesium Oxide 420 mg is identified by 1 NIH DSLD record, 336940, according to the retained record examined 2026-09-13; the label date is 2025-09-25.

Source record for tnvitamins Magnesium Oxide 420 mg
NIH DSLD labelNIH DSLD 336940
Registry snapshot2026-08-10
Label date2025-09-25
Physical stateCapsule
Barcode as filedX004C81D49
Source scanScanned label (NIH DSLD)
Calculation date2026-09-13

The barcode is retained as an identifier, not as proof of a retail match. A registry version count records the number held; it does not reveal what changed. The label date, registry snapshot and price-observation date describe different events.

Gaps in this record

What is not available for this label

tnvitamins Magnesium Oxide 420 mg has 1 unresolved data gaps in the retained NIH DSLD and price records as of 2026-09-13.

Dated missing-data statements
EntryKnown gap
1No confirmed US retail price matched to NIH DSLD 336940 (barcode X004C81D49) as of 2026-09-13.

An unmatched retail price describes our matching coverage. It does not establish that a product is unavailable. The elemental cost calculator can apply the same EC100 formula to a price you supply.