How Products Were Selected:
Products tested to represent those popular among readers of Consumerlab.com and commonly available nationally in the U.S. and Canada. ConsumerLab.com purchased products on the open market through retail stores, on-line retailers and direct sales companies. Products were not accepted directly from manufacturers.Testing Methods:
Products were tested in one or more independent laboratories for the following:
- Amount of magnesium, calcium and boron by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS).
- Amount of vitamin D (D2, D3) by High Performance Liquid Chromatography (HPLC) or Capillary Electrophoresis (CE).
- Amount of Vitamin K (K1, K2) by HPLC or CE.
- Lead, arsenic, cadmium and mercury by ICP-MS for all products.
- Disintegration of tablets (excluding chewable, sublingual and timed release formulations) utilizing United States Pharmacopeial (USP) <2040> recommendations entitled "Disintegration and Dissolution of Dietary Supplements."
- Disintegration time of enteric coated, time-release, and sustained release tablet, caplet and softgel formulations utilizing USP <2040> methodology for delayed-release (enteric-coated) tablets.
ConsumerLab.com may modify or use other appropriate test methods if necessary to test special product formulations.
The identities of the products were not disclosed to the laboratories performing the testing.
Passing Score:*
To be "Approved" for quality, a product had to meet the following requirements:
Magnesium-containing products:
Contain a minimum of 100% and not more than 135% of its labeled amount of elemental magnesium and meet any specific claims for magnesium (USP 40 Dietary Supplements Official Monographs). A product may not contain more than 125% of its labeled amount if the amount is over the daily upper limit (UL). Amount of magnesium found must also be consistent with form listed (based on scientifically known percentages of magnesium in magnesium compounds) when sufficient information about included compounds is provided on labels.
Calcium-containing products:
Contain a minimum of 100% and not more than 150% of its labeled amount of elemental calcium and meet any specific claims for calcium (USP 40 Dietary Supplements Official Monographs).
Boron-containing products:
Contain a minimum of 100% and not more than 160% of its labeled amount of elemental calcium and meet any specific claims for boron (USP 40 Dietary Supplements Official Monographs).
Vitamin D-containing products:
Contain a minimum of 100% and not more than 165% of its labeled amount(s) of vitamin D and meet any specific claims for vitamins D2 or D3. (USP 40 Dietary Supplements Official Monographs).
Vitamin K-containing products:
Contain a minimum of 100% and not more than 165% of its labeled amount(s) of vitamin K and meet any specific claims for vitamins K1 or K2 (as menaquinone-4 and/or -7) (USP 40 Dietary Supplements Official Monographs).
Heavy Metals: Products containing whole herbs and/or more than 250 mg of minerals per daily dose, straight mineral products and products containing rice bran, flower or brown rice must not exceed the following limits:
- Products marketed for use by children under 12 years of age may not exceed the State of California's Prop 65 limits for lead in dietary supplements of 0.5 mcg per recommended daily serving with an additional allowance of 0.8 mcg if the product contains more than 1,000 mg/day of calcium.
- Products with a single serving weight of less than 5 grams that are not marketed for use by children under 12 years of age, may not exceed the State of California's Prop 65 limits for lead in dietary supplements of 0.5 mcg per recommended daily serving (above which a warning regarding reproductive harm, birth defects, or cancer risks is required in California) with an additional allowance of 0.4 mcg if containing 250-999 mg/day of any combination of elemental calcium, magnesium and potassium or 0.8 mcg if containing more than 1,000 mg/day of any combination of these minerals. An additional allowance of 0.5 mcg is provided if containing 250-999 mg/day of whole herb (not extract) or 1.0 mcg if containing 1000 mg/day or more of whole herb (not extract). However, total lead allowance must not exceed 2 mcg per daily serving.
- Products with single serving weights of 5 grams or more that are not marketed for children under 12 years of age may not exceed 2.5 mcg per serving nor 4.0 mcg per daily serving.
- Contain less than 10 micrograms of total arsenic per daily serving (based on Canada’s limit per daily serving of a natural health product, and U.S. EPA and state of New Jersey limit in 1 liter of water). Products found to exceed this amount were tested for inorganic arsenic and must not contain more than 2.1 micrograms of inorganic arsenic per daily serving (Canada's additional limit in natural health products).
- If marketed for use by children under 12 years of age, may not exceed 3.0 micrograms of cadmium per recommended daily serving (based on Canada's limit for a child weighing 75lbs). If not marketed for use by children under 12 years of age, may not exceed 4.1 micrograms of cadmium per recommended daily serving (above which California's Prop 65 law requires a "reproductive harm" warning due to developmental toxicity and male reproductive harm.
- May not exceed 2 micrograms of inorganic mercury per daily serving (based on EPA limit for mercury in 1 liter of water).
- If applicable to the product, meet recommended USP <2040> parameters of disintegration of dietary supplement tablets (excluding sublingual, chewable and timed-release products).
- Enteric coated, time-release, and sustained release tablet, caplet and softgel formulations must meet recommended USP <2040> parameters for delayed-release (enteric-coated) tablets by visual inspection.
- Meet FDA labeling requirements.
* Passing scores allow for specific margins of technical error associated with each analysis. ConsumerLab.com reserves the right to disqualify a product at any time from passing its testing if it considers such product to display unacceptable variation in quality, present a safety risk or to provide misleading or inaccurate information in its labeling.
