Kefir
What it is
Milk kefir is a fermented milk food made with cultures that include bacteria and yeasts. The Codex fermented-milk standard describes kefir cultures prepared from kefir grains. This entry's scope is milk kefir; it does not assign milk nutrition values to water kefir.
What it does
The historical USDA example is LIFEWAY lowfat plain kefir, with 3.79 g of protein and 130 mg of calcium per 100 g. These figures describe that specific SR Legacy record. They are not a generic value for all kefir and are not a claim about the brand's current formulation.
Research context and ingredient forms
Fermentation and a demonstrated probiotic benefit are separate questions. NIH explains that live-culture foods do not necessarily contain organisms with proven probiotic benefits, and effects can be strain-specific. This entry does not infer a digestive-health benefit from the word kefir or from a nutrient table.
Using this information
For the product you buy, check the current ingredients, nutrition panel, and any identified cultures. The table below is a clearly labeled historical example, not a substitute for the current carton. Its basis is 100 g by weight, not 100 mL by volume.
Considerations
Milk is a major food allergen. Milk kefir should not be treated as an option for someone with a milk allergy merely because it is fermented.
Food sources and composition
| Nutrient | Amount and serving basis | Food and source |
|---|---|---|
| Energy | 43 kcal per 100 g edible portion | Kefir, lowfat, plain, LIFEWAY; Kefir, lowfat, plain, LIFEWAY SR Legacy April 2018; FDC published 2019-04-01 |
| Protein | 3.79 g per 100 g edible portion | Kefir, lowfat, plain, LIFEWAY; Kefir, lowfat, plain, LIFEWAY SR Legacy April 2018; FDC published 2019-04-01 |
| Total lipid (fat) | 1.02 g per 100 g edible portion | Kefir, lowfat, plain, LIFEWAY; Kefir, lowfat, plain, LIFEWAY SR Legacy April 2018; FDC published 2019-04-01 |
| Carbohydrate, by difference | 4.77 g per 100 g edible portion | Kefir, lowfat, plain, LIFEWAY; Kefir, lowfat, plain, LIFEWAY SR Legacy April 2018; FDC published 2019-04-01 |
| Calcium, Ca | 130 mg per 100 g edible portion | Kefir, lowfat, plain, LIFEWAY; Kefir, lowfat, plain, LIFEWAY SR Legacy April 2018; FDC published 2019-04-01 |
| Vitamin B-12 | 0.29 µg per 100 g edible portion | Kefir, lowfat, plain, LIFEWAY; Kefir, lowfat, plain, LIFEWAY SR Legacy April 2018; FDC published 2019-04-01 |
| Sodium, Na | 40 mg per 100 g edible portion | Kefir, lowfat, plain, LIFEWAY; Kefir, lowfat, plain, LIFEWAY SR Legacy April 2018; FDC published 2019-04-01 |
Scientific Research & References
- Kefir, lowfat, plain, LIFEWAY
2019 · USDA Agricultural Research Service
Limitations: Historical branded example, not generic kefir or a current manufacturer label. Food/preparation-specific composition; not clinical-trial evidence or an individual absorption estimate.
Source assessment recorded.
- USDA National Nutrient Database for Standard Reference, Legacy Release: Documentation
2018 · USDA Agricultural Research Service
Limitations: Historical dataset; values may be analytical, calculated, imputed, or assumed zero. Not clinical-outcome evidence.
Source assessment recorded.
- Standard for Fermented Milks, CXS 243-2003
2024 · Codex Alimentarius Commission, FAO/WHO
Limitations: Food identity standard; not proof of a clinical benefit from kefir.
Source assessment recorded.
- Probiotics: Fact Sheet for Health Professionals
NIH Office of Dietary Supplements
Limitations: Does not establish a kefir-specific treatment benefit or verify the strains in any current commercial product.
Source assessment recorded.
- Food Allergies
U.S. Food and Drug Administration
Limitations: Used for major-allergen identification and label awareness; not an individual allergy diagnosis.
Source assessment recorded.
Related dictionary entries
Products containing it
No label-specific product relationship has been reviewed for this entry.