Cranberry (Vaccinium macrocarpon) fruit contains phenolics, flavonoids, anthocyanidins, and ellagitannins. Some products are standardized based on quinic acid and others are standardized based on phenolics. Cranberry is most often used for prevention of urinary tract infections. It has no specific lactation-related uses. Cranberries appear to increase the milk content of polyphenols and total antioxidant capacity. Cranberry preparations are well tolerated as a food, although stomach discomfort and diarrhea can occur with large doses. Cranberry should be avoided in patients allergic to cranberries, blueberries and other Vaccinium species. Some cases of elevated INR have been reported in patients taking cranberry and warfarin.
Dietary supplements do not require extensive pre-marketing approval from the U.S. Food and Drug Administration. Manufacturers are responsible to ensure the safety, but do not need to prove the safety and effectiveness of dietary supplements before they are marketed. Dietary supplements may contain multiple ingredients, and differences are often found between labeled and actual ingredients or their amounts. A manufacturer may contract with an independent organization to verify the quality of a product or its ingredients, but that does not certify the safety or effectiveness of a product. Because of the above issues, clinical testing results on one product may not be applicable to other products. More detailed information about dietary supplements is available elsewhere on the LactMed Web site.