← All supplements

Vitamin B complex

Supplement vitamin blend energygeneral nutrition
Aka: B complex, B-50, B-100, bioactive B
Brands seen in Singapore: California Gold Nutrition, Life Extension, Thorne, Doctor's Best, NOW Foods
Third-party tested: Thorne lists a certified vitamin b complex product with NSF Certified for Sport.Certification is granted per product, so check the tub you actually own. Not being listed is not the same as failing.
Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.
How to use
What it’s for
B vitamins a diet misses · coenzymes in metabolism
When to take
Timing not addressed
Take with
Water · food lowers nicotinic-acid flushing
Pros & cons
Pros
  • Nad made from niacin serves 400+ enzymes
  • B6 coenzymes work in 100+ enzyme reactions
  • HSA allows energy-metabolism claims for b vitamins
Cons
  • B-50 and b-100 doses sit far above the rdas
  • B6 UL is 100 mg/day; efsa set 12 mg/day in 2023
  • Supplemental niacin UL is 35 mg/day, set on flushing
Sources
  1. NIH ODS — Niacin (Health Professional), updated November 18, 2022; read via web.archive.org capture 23 Aug 2026 — Introduction (NAD) · read 2026-08-27
    what it says
    “All tissues in the body convert absorbed niacin into its main metabolically active form, the coenzyme nicotinamide adenine dinucleotide (NAD). More than 400 enzymes require NAD to catalyze reactions in the body”
  2. NIH ODS — Niacin (Health Professional), updated November 18, 2022; read via web.archive.org capture 23 Aug 2026 — Health Risks from Excessive Niacin (flushing) · read 2026-08-27
    what it says
    “Thirty to 50 mg or more nicotinic acid typically causes flushing … Supplement users can reduce the flushing effects by taking nicotinic acid supplements with food, slowly increasing the dose over time”
  3. NIH ODS — Niacin (Health Professional), updated November 18, 2022; read via web.archive.org capture 23 Aug 2026 — Health Risks from Excessive Niacin (UL, Table 3) · read 2026-08-27
    what it says
    “The FNB has established ULs for niacin that apply only to supplemental niacin for healthy infants, children, and adults … These ULs are based on the levels associated with skin flushing … 35 mg”
  4. NIH ODS — Niacin (Health Professional), updated November 18, 2022; read via web.archive.org capture 23 Aug 2026 — Interactions with Medications (antidiabetes medications) · read 2026-08-27
    what it says
    “Large doses of nicotinic acid can raise blood glucose levels … nicotinic acid doses of 1.5 g/day or more are most likely to increase blood glucose levels in individuals with or without diabetes”
  5. NIH ODS — Vitamin B6 (Health Professional), updated June 16, 2023; read via web.archive.org capture 15 Aug 2026 — Introduction (coenzyme roles) · read 2026-08-27
    what it says
    “Vitamin B6 in coenzyme forms performs a wide variety of functions in the body and is extremely versatile, with involvement in more than 100 enzyme reactions, mostly concerned with protein metabolism”
  6. NIH ODS — Vitamin B6 (Health Professional), updated June 16, 2023; read via web.archive.org capture 15 Aug 2026 — Health Risks from Excessive Vitamin B6 (UL, neuropathy) · read 2026-08-27
    what it says
    “the FNB halved the dose used in these studies to establish a UL of 100 mg/day for adults … chronic administration of 1–6 g oral pyridoxine per day for 12–40 months can cause severe and progressive sensory neuropathy”
  7. NIH ODS — Vitamin B6 (Health Professional), updated June 16, 2023; read via web.archive.org capture 15 Aug 2026 — Health Risks from Excessive Vitamin B6 (EFSA 2023 opinion) · read 2026-08-27
    what it says
    “In 2023, the Panel … of the European Food Safety Authority (EFSA) … set an upper limit for vitamin B6 of 12 mg/day for all adults, including women who are pregnant or lactating”
  8. NIH ODS — Vitamin B6 (Health Professional), updated June 16, 2023; read via web.archive.org capture 15 Aug 2026 — Sources of Vitamin B6 (Daily Value note) · read 2026-08-27
    what it says
    “The DV for vitamin B6 is 1.7 mg for adults and children age 4 years and older”
  9. NIH ODS — Vitamin B6 (Health Professional), updated June 16, 2023; read via web.archive.org capture 15 Aug 2026 — Interactions with Medications (antiepileptics) · read 2026-08-27
    what it says
    “Some antiepileptic drugs, including valproic acid …, carbamazepine …, and phenytoin (Dilantin) increase the catabolism rate of vitamin B6 vitamers … pyridoxine supplementation (200 mg/day for 12–120 days) can reduce serum concentrations of phenytoin and phenobarbital”
  10. NIH ODS — Vitamin B6 (Health Professional), updated June 16, 2023; read via web.archive.org capture 15 Aug 2026 — Interactions with Medications (theophylline) · read 2026-08-27
    what it says
    “Patients treated with theophylline often have low plasma PLP concentrations, which could contribute to the neurological and central nervous system side effects associated with theophylline, including seizures”
  11. HSA — Health Supplements Guidelines GL-CHPB-3-001 (January 2026), clause 4.8 and Table 4 Vitamins Limits · read 2026-08-27
    what it says
    “Table 4: Vitamins Limits … Biotin 0.9mg … Folic acid 0.9mg … Nicotinic acid 15mg … Nicotinamide 450mg … Vitamin B1 100mg … Vitamin B2 40mg … Vitamin B5 (pantothenic acid) 200mg … Vitamin B6 100mg … Vitamin B12 0.6mg”
  12. HSA — Health Supplements Guidelines GL-CHPB-3-001 (January 2026), List of Health Claims, row 42 · read 2026-08-27
    what it says
    “Help in energy metabolism in the body • Vitamin B2, B3, B5, B6, B12 • Magnesium, zinc”
  13. HSA — Guidelines on Prohibited and Restricted Ingredients in HS and TM (October 2025), Annex B rows 47 (Folic acid), 76 (Nicotinic acid), 111 (Vitamin B6) · read 2026-08-27
    what it says
    “111. Vitamin B6 — Restricted use in HS and TM … not provide more than 100mg … 76. Nicotinic acid … not provide more than 15mg … 47. Folic acid … not provide more than 0.9mg”
  14. iHerb Singapore — 'Vitamin B Complex' category page, default order, 236 results · read 2026-08-27
    what it says
    “California Gold Nutrition, Vitamin B Complex with Folate, Biotin, Pantothenic Acid, and Vitamin B6 … Life Extension, BioActive Complete B-Complex … Thorne, Basic B Complex … Doctor's Best, Fully Active B Complex … NOW Foods, B-50”
Report a correction View as JSON

Updated 2026-08-30. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.