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Cheapest test that includes it£695.00Full Vitamin Screen at Better2Know, all-in with a vein draw
Tests compared2from 1 provider, checked 29 October 2026
What it measures
The test measures vitamin B3 in the blood, as niacin, nicotinamide or the forms the body makes from them. Labs differ in which form they measure. The body can also make some B3 from the amino acid tryptophan.
Why people test it
Measured when low intake is suspected, for example with heavy alcohol use or a very restricted diet.
Part of some nutrition panels covering the B vitamins.
Typical range
Ranges vary by lab, method, age and sex, and depend on which form of B3 is measured. Your report shows the lab's own range.
Finger-prick or vein?
Taken from a vein. Providers offer it only as a vein draw, at a clinic or with a visiting nurse.
Every Vitamin B3 test, cheapest first
Cheapest first, whether the test is of Vitamin B3 alone (marked "single-marker test") or a panel that includes it. Each price is all-in: the test and the cheapest way to have the blood taken that suits this marker, before any discount code.
Vitamin B3 tests and their all-in prices
Test
All-in
Link
Full Vitamin Screen Better2Know · 10 markers · checked 29 October 2026
Cheapest per doseBest value under 6 months' supplyNiacinamide · 180 capsules · 180 servings · 500 mg a servingDetails and price history →HPMC capsule, the listing says
· 180 capsules · 180 servings · 500 mg a serving