The Healthspan Map · Nutrient

Biotin (B7)

Linked to getting too little

Where a shortfall of Biotin (B7) is linked — 3 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or lever	Direction	Strength	Evidence type	What was found	Source
Biotin (B7)	Eat enough of	Moderate	Established clinical	Adult deficiency causes neurological findings including depression, lethargy and hallucinations.	NIH ODS – Biotin (opens in a new tab)
Biotin (B7)	Eat enough of	Moderate	Review / narrative	Biotin deficiency causes brittle nails, alopecia and scaly dermatitis (but supplements only help if truly deficient).	Biotin & hair/nails (opens in a new tab)
Biotin (B7)	Eat enough of	Emerging	Systematic review	Higher dietary B-vitamin intake, especially biotin, is associated with lower stress symptoms.	B-vitamins/EFA/mineral stress review (McCabe et al. 2017) (opens in a new tab)

Where an excess of Biotin (B7) is linked — 1 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or lever	Direction	Strength	Evidence type	What was found	Source
Biotin (B7)	Don't overdo	Moderate	Established clinical	High supplemental biotin caused a falsely LOW troponin result and a missed heart attack — the FDA reported one death; also distorts NT-proBNP and many hormone assays.	FDA Safety Communication (2017) – Biotin (opens in a new tab)