Reviewed and updated 21 September 2026.
Nitrate occurs naturally in vegetables and water. Nitrate and nitrite salts are also used as food preservatives, including in some cured meats, where they help control harmful bacteria. EFSA explains their role in food.
Which E numbers are nitrates and nitrites?
| E number | Additive |
|---|---|
| E249 | Potassium nitrite |
| E250 | Sodium nitrite |
| E251 | Sodium nitrate |
| E252 | Potassium nitrate |
Source: UK list of approved additives. Sulphur dioxide and sulphites, E220–E228, are a different group and were incorrectly included in the earlier version of this article.
Food and personal symptoms
This page is a food-label reference. It does not establish that nitrates cause an individual’s headaches, or provide advice about nitrate medicines. The earlier unsupported headache statistic and dietary restrictions have been removed.
If you suspect a food is causing symptoms, discuss your observations with a GP or registered dietitian before making a restrictive diet change.
See also nitrates in vegetables.