Mineral forms on the label: bisglycinate, citrate, oxide and L-threonate

Minerals such as magnesium, zinc or iron are usually present in food supplements as a compound in which the mineral is bound to another molecule, its binding partner. This can be an amino acid, an organic acid or oxygen. One exception is elemental iron, which Annex II to Directive 2002/46/EC also permits. In Naturlabs products, all minerals are in compounds, and the name of the form on the label, such as zinc bisglycinate or copper citrate, tells you what the mineral is combined with.

The permitted sources of vitamins and minerals for food supplements are set out in Annex II to Directive 2002/46/EC and its later amendments. So manufacturers do not choose from an unlimited range, but from permitted forms.

A bisglycinate is a mineral bound to two molecules of glycine, the simplest amino acid. You can recognise it on the label by its name, for example zinc, iron, calcium or magnesium bisglycinate.

The word chelate refers to a compound in which the mineral is bound to the same molecule at two or more points, forming a ring structure. Bisglycinates are chelates, which is why shops often call them chelated minerals. It is more precise, however, to name the specific compound, because there are several kinds of chelate.

In the Naturlabs range you will find zinc bisglycinate in Elements., iron bisglycinate in Iron. and calcium bisglycinate in Calcium + D3 + K2. Magnesium + B6 contains a mix of magnesium bisglycinate and magnesium oxide.

A citrate is a salt of citric acid. The mineral is bound to an acid you know from citrus fruit, which is also widely used in food production. On the label you will find it as magnesium citrate, copper citrate or calcium citrate.

At Naturlabs, copper citrate is in Elements., where one capsule contains 1 mg of copper, and magnesium citrate is in D3 + K2, where one capsule contains 60 mg of magnesium.

Magnesium oxide is a compound of magnesium and oxygen. The binding partner is small and light, so one gram of the oxide contains more magnesium than forms bound to an amino acid or an organic acid.

Magnesium + B6 contains a mix of magnesium bisglycinate and magnesium oxide, together 375 mg of magnesium in 2 capsules, which is 100% NRV. The label shows the total amount of magnesium, regardless of which part of the mix it comes from.

Magnesium L-threonate is magnesium bound to L-threonic acid. On the label you will also find it under the trade name of the raw material, Magtein®. Magnesium makes up only a smaller part of the weight of this compound.

At Naturlabs, Magtein® is in Focus., which contains 144 mg of magnesium in 3 capsules daily. You will find potassium iodide in Iodine + L-tyrosine.

Besides the mineral, every compound also contains the binding partner, which has its own weight. If a label gave only the weight of the compound, you could not compare how much of the mineral a product contains. That is why the ingredients table states the amount of the nutrient itself and its share of the nutrient reference value.

In practice: 15 mg of zinc in Elements. means 15 mg of zinc, not 15 mg of zinc bisglycinate. Likewise, 28 mg of iron in Iron. is the amount of iron, not of the whole compound.

• Find the recommended daily dose and the number of capsules the figures refer to.
• In the ingredients table, compare the amount of the mineral itself per daily dose.
• Check the form and, if given, the trade name of the raw material.
• Work out how many days a pack lasts and what one day costs.
• If you take several products, add up the same nutrients from all of them.

The form tells you what the compound is made of. It does not tell you that a product does more or works faster. The EU list of authorised health claims contains no claim relating to a specific form of a mineral. A claim always belongs to the mineral itself, for example: Zinc contributes to the normal function of the immune system. The condition for using this claim relates to the amount of zinc per daily dose, not to its form.

The same applies to vitamins. Methylcobalamin and cyanocobalamin are two forms of vitamin B12. Folate can appear on a label as folic acid or as (6S)-5-methyltetrahydrofolate, at Naturlabs under the trade name Quatrefolic®. In Magnesium + B6, vitamin B6 is in the form of pyridoxal 5'-phosphate. Here too, the claims belong to the vitamin, not to its form.