Missing is not zero. A zero reports a value supplied or calculated as zero under the source’s rules. Missing means Foodmanac does not have a compatible measured value for that nutrient in that specific record.
Why this distinction matters
Nutrition databases combine information from laboratory analyses, surveys, package labels and other documented sources. Not every source reports every nutrient. If a nutrient is absent from a record, replacing that blank with zero would create a claim the source did not make.
For example, if a record does not include vitamin K, the correct conclusion is “vitamin K was not available in this record,” not “this food contains no vitamin K.” Another preparation, cultivar, brand or source may contain a measured value.
What a measured zero means
A displayed zero can come from a reported measurement, a value below a reporting threshold or permitted label rounding. It should be read according to the source context. USDA’s branded-food documentation explains that label rounding can produce a reported zero even when laboratory analysis might detect a small amount.
This is one reason Foodmanac preserves the data state and source instead of converting every empty field to zero.
Four data states readers may encounter
| Display state | What it means | What it does not mean |
|---|---|---|
| Measured number | The source supplied a numeric value for this record. | It is not a universal value for every variety or preparation. |
| Measured zero | The source value is zero under its reporting and rounding rules. | It does not always prove complete chemical absence. |
| Missing | No compatible measured value is available in this record. | It does not mean zero. |
| Not established | A comparison value such as %DV cannot be calculated. | The measured amount may still be available. |
Why two records for the same food can differ
- Preparation: raw, boiled, baked and fried foods are separate records.
- Water content: cooking or drying changes nutrient concentration per 100 g.
- Variety and growing conditions: plant foods naturally vary.
- Brand formulation: packaged products can use different ingredients or fortification.
- Sampling and analysis: sources may use different samples, dates or methods.
- Rounding: label rules can affect small reported values.
These differences are not automatically errors. They are reasons to keep the food description, preparation, reference amount and source next to the number.
How Foodmanac handles missing and zero values
- The original food and preparation remain separate.
- Measured values are stored with their units and source identifiers.
- Missing values remain missing instead of being converted to zero.
- Small negative “by difference” source values caused by analytical rounding are displayed as zero with an explanatory note.
- Calculations use compatible measured values only.
You can inspect these details on any record in Explore Foods. For a fuller explanation of the database rules, see the Foodmanac Methodology.
The practical rule
When a nutrient is missing, do not treat the blank as a nutrient claim. Search for a better-matched record, confirm the preparation, and review the source. When a value is zero, keep the source’s rounding and reporting rules in mind.