Labdoor analyzed 10 of the best-selling B-Complex supplements in the United States for B-vitamin content and heavy metal (arsenic, cadmium, lead, mercury) contamination.
All B-Complex supplements in this batch analysis claimed thiamin (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), pantothenic acid (vitamin B5), vitamin B6, biotin (vitamin B7), folate or folic acid (vitamin B9), and vitamin B12. Overall, measured B-vitamin values deviated from label claims by an average of 33%. In most cases, products had more of each B-vitamin than they claimed. 8 of 10 products met daily intake recommendations for all their claimed B-vitamins in 1 serving1.
7 products exceeded the established Tolerable Upper Intake Level (UL) for niacin, which can mean an increased risk for the common minor side effect of redness and flushing of the skin2, and 1 product exceeded the UL for vitamin B6, established based on a possible risk for nerve damage3. All products passed heavy metal screenings.
Analytical Chemistry Methods: CE (vitamins B1, B2, B3, B5, B6), Gravimetry (biotin), ICP-OES (vitamin B9), LC-FLD (vitamin B12), ICP-MS (arsenic, cadmium, lead, mercury).
Only 3 of 10 products recorded B-vitamin levels that met all of their B-vitamin label claims.
Overall, measured B-vitamin values ranged from -47% to +258% vs. their respective label claims, deviating from label claims by an average of 33%. In most cases, products had more of each B-vitamin than they claimed. Of the B-vitamins, folate (vitamin B9) exhibited the highest label claim deviation; measured values deviated from label claims by an average of 58%.
All 10 products passed heavy metal screens for arsenic, cadmium, lead, and mercury.
All products passed heavy metal screens. This means that each product's heavy metal recordings per serving passed Labdoor's standards. Labdoor's standards for heavy metal content are derived from California Proposition 65's4 proposed and established MADLs (Maximum Allowable Dose Levels) and NSRLs (No Significant Risk Levels): no more than 10 mcgday of inorganic arsenic, 4.1 mcgday of cadmium, 0.5 mcgday of lead, and 0.3 mcgday of mercury (proposed).
B-Complex products averaged 100 (out of 100) in Nutritional Value scores.
B-Complex products in this batch recorded minimal quantities of calories, fats, carbohydrates, and sugars.
7 products exceeded the UL for niacin in 1 serving, which can mean an increased risk for minor redness and flushing of the skin.
Products in this batch recorded B-vitamin levels that fell within established Tolerable Upper Intake Levels (ULs), except in the following cases:
7 products exceeded the UL for niacin of 35 mg in 1 serving, which can mean an increased risk for the common minor side effects stomach upset or redness and flushing of the skin2. Niacinamide and inositol hexanicotinate might be less likely to cause side effects compared to nicotinic acid, but research is inconclusive6.
1 product exceeded the UL for vitamin B6 of 100 mg in 1 serving, established based on a possible risk for nerve damage. The NIH notes that "although several reports show sensory neuropathy occurring at doses lower than 500 mgday, studies in patients treated with vitamin (average dose of 200 mgday) for up to 5 years found no evidence of this effect"3.
No synthetic sweeteners, artificial colors, or controversial preservatives were recorded in this batch.
Average measurements for biotin and vitamin B12 were 340 mcg and 300 mcg, respectively, much higher than their established AIs for adults of 30 mcg and 2.4 mcg.
In this batch analysis, these are the associated averages for specific B-vitamin content per serving: thiamin (44 mg), riboflavin (23 mg), niacin (53 mg), pantothenic acid (51 mg), vitamin B6 (35 mg), biotin (340 mcg), folate or folic acid (620 mcg), vitamin B12 (300 mcg). 8 of 10 products met daily intake recommendations, based on Recommended Daily Allowances (RDAs) and Adequate Intakes (AIs), for all their claimed B-vitamins in 1 serving1.
- 1 NIH. (2016). Dietary Supplement Fact Sheets.
- 2 Linus Pauling Institute. (2013). Niacin. Micronutrient Information Center.
- 3 NIH. (2016). Vitamin B6 Dietary Supplement Fact Sheet.
- 4 CA OEHHA. (2016). Proposition 65.
- 5 Academy of Nutrition and Dietetics. (2015). What are B-vitamins and folate?.
- 6 University of Maryland Medical Center. (2015). Vitamin B3 (Niacin).