Source Naturals Magnesium Citrate 133 mg

Mass budget · computed; capsule comparison · modelled

What the declared salt would weigh

Source Naturals Magnesium Citrate 133 mg declares 133 mg of elemental magnesium per serving in NIH DSLD 295971, requiring 823.02–1,176.99 mg of magnesium citrate under the salt model calculated 2026-09-13.

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

Source Naturals Magnesium Citrate 133 mg has 11 published fields below, traced to NIH DSLD 295971 and the 2026-08-10 registry snapshot, with calculations dated 2026-09-13.

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

Source Naturals Magnesium Citrate 133 mg retains 1 magnesium-related rows in NIH DSLD 295971, including 1 rows selected for the primary serving, from label 2023-08-23, examined 2026-09-13.

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

Source Naturals Magnesium Citrate 133 mg works out to 30–90 days per package at the label's own serving and filed frequency of 1–3 servings per day, according to label 2023-08-23, calculated 2026-09-13.

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.

Percent daily value · observed and computed

The label's percent daily value, recomputed

Source Naturals Magnesium Citrate 133 mg files 1 magnesium percent-daily-value entries in NIH DSLD 295971; the check below applies the group-specific references in 21 CFR 101.9 to its 133 mg primary serving, calculated 2026-09-13.

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

Source Naturals Magnesium Citrate 133 mg lists 4 other ingredients in NIH DSLD 295971, label dated 2023-08-23, examined 2026-09-13.

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

Source Naturals Magnesium Citrate 133 mg has 4 target-group entries in NIH DSLD 295971, label dated 2023-08-23, examined 2026-09-13.

Provenance · observed

Registry record, versions and scanned label

The registry holds 3 versions of this label for Source Naturals Magnesium Citrate 133 mg, according to the retained record examined 2026-09-13; the label date is 2023-08-23.

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

Source Naturals Magnesium Citrate 133 mg has 1 unresolved data gaps in the retained NIH DSLD and price records 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.