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Vitamin B3 (niacin / nicotinic acid)

Essential nutrient with EFSA claims; high-dose nicotinic acid lowers LDL and raises HDL, cardiovascular outcome trials however null.

Why

Vitamin B3 has two main forms: nicotinic acid (niacin, causes flushing) and nicotinamide (niacinamide, no flushing, covered separately). At dietary doses both have EFSA-authorised health claims for energy metabolism, nervous system, psychological function, mucosa and tiredness/fatigue. At high doses (≥1 g/day) nicotinic acid has the strongest lipid-modifying effect of any single agent on HDL (raises 15–25%) and meaningful LDL reduction, but the AIM-HIGH and HPS2-THRIVE cardiovascular outcome trials were null/harmful when added to statins. Use for lipids has shrunk substantially as a result.

How it works

Precursor (via niacin pathway) to NAD+ and NADP+, central cofactors in over 400 enzymatic reactions. High-dose pharmacological effect on lipids is via inhibition of hepatic diacylglycerol acyltransferase 2 (DGAT2) and adipocyte hormone-sensitive lipase.

Expected onset · Flush within minutes; lipid effects over 4–8 weeks

How to take

Dosage

RDI: 14–16 mg NE/day. Lipid context (specialist only): 1–2 g/day immediate-release or 1–2 g/day extended-release (Niaspan).

Timing

With meals to reduce flushing (and ideally with aspirin 30 min before to blunt flush, when used at lipid doses)

On the label

Distinguish 'nicotinic acid / niacin' (flushing, lipid-active) from 'niacinamide / nicotinamide' (no flush, no lipid effect, separate dermatology/oncology evidence). Stated milligrams.

Ideal for

Adults seeking general B-vitamin support; carefully-selected dyslipidaemia patients (specialist context, particularly statin-intolerant), but cardiovascular outcome data is unfavourable when added to statins.

Safety

Flushing (uncomfortable but harmless) is universal at therapeutic doses, pre-medicate with aspirin and take with food. Hepatotoxicity, hyperglycaemia, hyperuricaemia (gout) and elevated homocysteine at high doses. AIM-HIGH/HPS2-THRIVE: adding niacin to statin therapy did not reduce CV events and increased AE rates, lipid-context use should be specialist-supervised. Avoid in active peptic ulcer, severe hepatic disease, gout. Pregnancy: dietary doses fine; high-dose supplementation should be avoided.

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Evidence

At a glance

EFSA-authorised claims cover five functions. AIM-HIGH 2011 (n=3,414) and HPS2-THRIVE 2014 (n=25,673), both NEJM, found no cardiovascular benefit when extended-release niacin was added to statin therapy, with HPS2-THRIVE showing increased serious adverse events. This shifted clinical use of niacin for lipids substantially: the lipid signal is real, the outcome benefit on top of statins is not.

Where to get it

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