Vitamin D, B12, and folate: what labs may mean for hair
D, B12, folate — what labs can and cannot explain about shedding or thinning.
Before every “hair vitamin,” how D, B12, and folate fit a sensible check-up with your doctor.
Insights
What might be behind your hair loss?
Worried about sudden shedding, gradual thinning, hormones, blood tests, or an irritated scalp? Start below, then search — we cover medicines, office procedures, and long-term hair support in plain language. This is education, not a substitute for an exam with your doctor.
First step
Start here
Choose what matches you most. Then use search when you want to narrow down.
- Go to guideI’m shedding suddenlyHeavy or diffuse shedding after stress, illness, or pregnancy — what that can mean.
- Go to guideMy hair is thinning graduallySlow thinning, part widening, or pattern change — how causes are sorted out.
- Go to guideI think hormones or blood tests may be involvedFerritin, thyroid, and other labs — when they help and when they don’t.
- Go to guideI’ve already had treatment and still have concernsMedicines, PRP-style procedures, or a transplant — where to read next and how your care team fits in.
Results
Thyroid and hair loss: what patients should know
Under- or overactive thyroid can change shedding or texture — and “normal” TSH still leaves other causes on the table.
What TSH and related tests are for — and when shedding continues despite normal labs.
Ferritin and hair loss: what your result can and can’t tell you
One lab value for stored iron — helpful in context, not a full diagnosis of why hair is shedding.
Low ferritin can matter for shedding — not a DIY iron prescription. Basics before you supplement.