Main Active Ingredients in UK Iron Tablets
In the UK, the most common active ingredients in iron tablets, both prescribed and over-the-counter, are different forms of iron salts. These compounds are chosen for their effectiveness in increasing the body's iron stores and treating conditions like iron-deficiency anaemia.
Ferrous Sulfate
Ferrous sulfate is a widely used and highly effective form of iron supplement. It is often considered the 'gold standard' for oral iron therapy. The NHS frequently prescribes ferrous sulfate tablets, which typically contain 200mg of dried ferrous sulfate, equivalent to 65mg of elemental iron. It works by replenishing the body's stores, helping to produce healthy red blood cells that transport oxygen around the body. Some formulations may be slow-release to minimise stomach upset, though standard release is common.
Ferrous Fumarate
Ferrous fumarate is another highly absorbed iron salt used to treat and prevent iron-deficiency anaemia. It is available in various strengths, with tablets containing 210mg or 322mg of ferrous fumarate, providing 69mg or 106mg of elemental iron, respectively. Ferrous fumarate is also available in capsules or liquid form and is known for its effectiveness, though some users may experience milder gastrointestinal side effects compared to sulfate.
Ferrous Gluconate
Less commonly used but still available, ferrous gluconate is another iron salt that can be prescribed. It is a soluble salt of ferrous iron that is typically less concentrated than ferrous sulfate or fumarate. It may be offered to patients who experience more significant gastrointestinal issues with the higher elemental iron content of other forms, but it is not as widely used in the UK market.
Other Iron Compounds
For individuals with a sensitive stomach or those who cannot tolerate standard ferrous salts, alternative formulations exist, including iron polymaltose and polysaccharide iron complexes. These are often found in branded supplements like Maltofer or Active Iron and are designed for improved absorption with fewer gastrointestinal side effects. Some of these more advanced formulas use a protein carrier to deliver iron directly to the absorption site in the small intestine, bypassing the stomach. Spatone, an iron-rich water, provides a natural, easily absorbed source of iron and is often combined with Vitamin C.
Synergistic Ingredients for Enhanced Absorption
Iron tablets in the UK often don't contain just iron. Many popular brands add other ingredients to boost efficacy and address potential side effects:
- Vitamin C (Ascorbic Acid): Significantly increases the absorption of iron from the digestive tract. Many iron tablets, such as those from Vitabiotics, include a dose of Vitamin C for this reason. The NHS also suggests taking iron with orange juice.
- Folic Acid (Vitamin B9): Often included in combination supplements, especially those for pregnant women. Folic acid is essential for red blood cell formation, working alongside iron to combat anaemia.
- Vitamin B12: Similar to folic acid, B12 is vital for red blood cell production. Including it helps support overall blood health and can be beneficial for those with specific dietary restrictions.
- Zinc and Copper: Some multivitamin formulations that include iron also add zinc and copper, as these minerals play roles in various bodily functions, including immune health and blood formation.
Comparison of Common UK Iron Tablet Types
| Feature | Ferrous Sulfate | Ferrous Fumarate | Iron Polymaltose / Polysaccharide Iron Complex |
|---|---|---|---|
| Elemental Iron Content | Medium (e.g., 65mg from 200mg salt) | Medium to High (e.g., 69-106mg from 210-322mg salt) | High (e.g., 100mg elemental from 370mg complex) |
| Absorption Rate | Good, especially on an empty stomach | Good, often with food to reduce side effects | High, often less affected by food |
| Gastrointestinal Side Effects | Common (constipation, nausea, discomfort) | Common, but potentially milder than sulfate | Less common and often milder |
| Availability | Prescription and over-the-counter | Prescription and over-the-counter | Mostly over-the-counter, often branded |
| Price | Generally lower | Moderate | Higher (premium products) |
Important Considerations and Side Effects
Regardless of the active ingredient, taking oral iron supplements can cause side effects. The most common issues include constipation, nausea, stomach pain, and dark stools. The severity of side effects is often dose-related, and some individuals may need to switch to a different type of iron or adjust their dosage.
To manage side effects:
- Take with food: While absorption is best on an empty stomach for ferrous salts, taking them with or after a meal can reduce gastrointestinal upset, though absorption may decrease.
- Stay hydrated and eat fibre: Drinking plenty of water and increasing dietary fibre intake can help prevent constipation.
- Consider dose frequency: Some evidence suggests that taking iron on alternate days can optimise absorption and reduce adverse effects.
It is crucial to remember that iron overdose can be dangerous, especially for children. Always store iron supplements out of sight and reach of children and follow dosage instructions carefully.
For more detailed information on iron deficiency and treatment, you can refer to the official NHS website.
Conclusion
Iron tablets in the UK primarily contain ferrous sulfate or ferrous fumarate, which are well-established and effective treatments for iron-deficiency anaemia. For those who experience significant side effects, newer formulations with iron polymaltose or polysaccharide complexes offer a gentler alternative. Many supplements also include co-factors like Vitamin C and B vitamins to maximise absorption and support overall blood health. The choice of supplement depends on individual tolerance, the severity of the deficiency, and clinical advice. Always consult a healthcare professional before starting any iron supplementation to ensure it is the right treatment for your specific needs.
