Supplements

riboflavin decreases homocysteine

Insufficient Supplements 🔬 Includes disconfirming

RefutedContestedStrong support

consensus score 0.70

⚖️ Thin evidence — read the needle loosely. The score shows which way the studies lean, but there are too few independent, high-quality ones to place it firmly. Expect this to move as better evidence arrives.

📅 Last reviewed: 2026-07-15 ⓘ

Evidence ladder

How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."

Top evidence so far: Human trials (RCT / n-of-1)

MechanismIn-vitroAnimalObservationalRCTMeta-analysis

How the studies fall

2 support 0 contradict 1 tested null 0 mixed · 3 sources, 1 independent group

What the evidence shows

Riboflavin (~1.6 mg/d) lowers homocysteine and systolic blood pressure specifically in MTHFR 677TT homozygotes (riboflavin is the MTHFR enzyme's FAD cofactor).

The evidence (4)

Source	Grade	Stance	Quality	Finding
Rooney M, Bottiglieri T, Wasek-Patterson B, McMahon A, Hughes CF, McCann A, Horigan G, Strain JJ, McNulty H, Ward M 2020 · Biochimie	RCT	supports	moderate	Secondary analysis of stored plasma from prior Ulster BP-lowering RCTs (abstract-grade). Riboflavin 1.6 mg/d (n 24) vs placebo (n 23), 16 wk, MTHFR 677TT adults: 'In response to riboflavin, SAM (P = 0.008) and cystathionine (P = 0.045) concentrations increased, with no responses in other one-carbon metabolites observed.' The LC-MS/MS panel was methionine, SAM, SAH, betaine, choline, cystathionine; no homocysteine response to riboflavin is reported in the abstract (full text could show a null, which would be contradicts - cannot-tell from available text). Homocysteine appears only cross-sectionally: 'plasma homocysteine was higher (P = 0.043) in TT, compared to CC individuals' (n 115). Population drawn from the RCTs already counted here (Horigan 2010 / Wilson 2013 lineage), same McNulty/Ulster group.
jingo-2020 2020 · BMC medicine	observational	tested-null	moderate	Riboflavin status modulates 677TT hypertension risk across adulthood.
horigan-2010 2010 · Journal of hypertension	RCT	supports	moderate	Riboflavin lowered systolic BP ~13 mmHg in 677TT (none in CC/CT).
wilson-2013 2013 · Hypertension (Dallas, Tex. : 1979)	RCT	supports	moderate	SBP -5.6 mmHg on top of antihypertensives in 677TT (P=0.033).

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Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.