New allowable limits for the use of boron in oral natural health products:
Health Canada has set a maximum limit of 0.7 mg of elemental boron equivalents per daily dose for boron as a trace mineral as part of an “Adults only” multivitamin-multimineral natural health product.
In cases where boron is included as one medicinal ingredient in multiple ingredient natural health products for a specific therapeutic purpose, Health Canada has set a limit of no more than 3.36 mg of elemental boron equivalents per daily dose. Such boron-containing natural health products will be labelled “Adults only” and will be contraindicated for pregnant or breast-feeding women. A caution to consult with a health care practitioner prior to use in cases where an estrogen-dependent cancer exists, will also be on the label. In this situation, Health Canada is taking a precautionary approach, despite the fact that the maximum dose is at the range of the average daily intake of boron naturally occurring in food and water.
More information available here: Boron as a Medicinal Ingredient in Oral Natural Health Products.