Iron in Huel and the Effects of Antinutrients and Vitamin C

Despite concerns about the high iron content and the effects of ingredients that affect the body’s iron absorption, the iron content in Huel products can be classified as optimal. The following information is intended to resolve any doubts some users have expressed about the amount of iron provided by Huel products.

The nutrient reference value (NRV) for iron is 14 mg per day [1] . The NRV of a nutrient is the amount that most people need. A good iron supply is crucial for the transport of oxygen through red blood cells as well as for muscle contraction and nerve impulses. If the iron concentration in the blood is too low, one speaks of iron deficiency anemia.

Hemochromatosis is a condition that causes the body to accumulate iron. This is mostly genetic and cannot be controlled and is associated with liver cirrhosis, cardiomyopathy, arthritis and diabetes. The disease is most common in people of northern European origin, affecting around one in 250 people. In many people the disease is undiagnosed and symptoms may not appear until the affected person is exposed to high iron intake [2] .

There are ingredients in food that impair the absorption of iron and some other minerals and reduce their bioavailability. As a result, there is concern that the iron content in Huel products may be insufficient. Bioavailability describes the amount of a nutrient that is absorbed and effective in the body. Ingredients that have a negative effect on the absorption of nutrients are also known as anti-nutrients. These food ingredients reduce the nutritional value of other nutrients, although they themselves have nutritional benefits.

Huel Powder contains around 39 mg iron (based on a consumption of 2,000 kcal), which is 280% of the NRV. This value may seem high, but there are a number of factors that play a role that affect iron status. It is important to take these into account when demonstrating that regular consumption of Huel products provides the optimal amount of iron.

Huel contains non-heme iron

Heme iron is a type of iron that occurs mainly in animal products and makes up around 40% of the total iron content there [3] . The rest is accordingly non-heme iron. In most plants, iron occurs only in the form of non-heme iron. All iron in Huel products is naturally contained in the main ingredients and is not added. Since Huel products contain no ingredients of animal origin, they are entirely non-heme iron.

The bioavailability of non-heme iron is more strongly influenced by other nutritional factors than that of heme iron [4, 5] . The amount of non-heme iron absorbed also depends on how much iron is already in the body. If the iron value is low, the body absorbs more iron from food; if there are sufficient iron reserves, it is less [6] . Usually, heme iron is more easily absorbed than non-heme iron. The amount absorbed is 15–35% compared to 2–20% [7, 8] . The uptake of heme iron is not regulated, so that the body absorbs more than necessary if it is consumed too much. For this reason, people with hemochromatosis benefit from a vegan diet.

Phytic acid and iron

The main antinutrient that affects the absorption of iron and other minerals is phytic acid. Phytic acid, also called hexa-phospho-inositol, is a naturally occurring storage form of phosphorus in plant seeds. The bound form is called phytate. Oats, flaxseeds, quinoa, brown rice and black beans in our products are rich in phytic acid. Phytic acid is often portrayed negatively because of its anti-nutrient effect, which inhibits the absorption of some minerals such as iron, zinc and manganese. However, their health benefits are often overlooked. Phytic acid is an antioxidant [9–11] with proven anti-carcinogenic effects [12]. Iron can become a free radical and thus contribute to oxidative stress, which causes damage in the body. The ability of phytic acid to bind and absorb iron is therefore an advantage. [13] Phytic acid can also bind heavy metals (e.g. cadmium and lead) and prevent their accumulation in the body. You can learn more about this in our article Phytonutrients in Huel .

The extent to which phytic acid reduces the bioavailability of iron varies. Other food components also play a role and influence the rate of absorption. Based on intake data and isotope studies, an approximate bioavailability of 14–18% for a mixed diet and 5–12% for a vegetarian diet was determined in people without iron reserves [4, 5] . The recommended iron intake for vegetarians can be 1.8 times higher than that for non-vegetarians [5, 14] . However, there seems to be no connection between a vegetarian diet and an increased risk of iron deficiency [15]. As a result, other factors clearly come into play here, as well as other food components that promote iron absorption (see below).

Grinding grains and removing the bran reduces the phytic acid content of cereals and seeds. [16] This is also the case with Huel, as the oats are finely ground and the amount of phytic acid they contain is significantly reduced. In addition, a large part of phytic acid (37–66%) is broken down in the stomach and small intestine. [17]

Calcium and iron

It has been found that calcium reduces the absorption of both heme iron and non-heme iron, with the latter being more severely affected [18, 19] . However, the effect is less pronounced than with phytic acid and a minimum concentration of calcium is required for an inhibitory effect to occur [20] . Furthermore, an adjustment takes place over time. It was found that increased calcium intake had a reducing effect on iron levels for up to twelve weeks, but this was then reversed by increased absorption of non-heme iron [6, 21] .

Huel products are high in calcium, some of which is naturally occurring and some of which is added with the micronutrient mix in the form of calcium carbonate. However, since Huel is also rich in iron and an adaptation takes place, the influence of calcium on iron absorption is rather small.

Polyphenols and iron

Some polyphenols have also been shown to reduce the bioavailability of iron. [5] Huel products contain some antioxidant polyphenols from the main ingredients that can inhibit iron absorption. However, the impact is minimal.

Vitamin C and iron

The beneficial effect of vitamin C on the absorption and bioavailability of iron has been comprehensively scientifically proven, as has the fact that vitamin C supplementation increases iron levels more than iron supplements [22] . Vitamin C, also known as ascorbic acid, is therefore an essential compound to counteract the effects of antinutrients, especially in vegetarians. In fact, the effect of vitamin C, which is itself an antioxidant, is so strong that a clear reversal effect on the absorption-inhibiting effect of phytic acid was found. In one study, phytic acid reduced iron absorption by up to 50%, but this could be compensated for with an additional 30 mg of vitamin C [23] .

Is Huel’s iron content optimal?

All iron in Huel products is non-heme iron, which is naturally found in key ingredients. Huel Powder v3.0 and Black Edition have a high iron content of around 40 mg per 2,000 kcal, which corresponds to 280% of the NRV. The amount of iron in Huel Ready-to-Drink and Hot & Savor is significantly lower, but is still more than sufficient and exceeds the NRV.

Theoretically, a daily consumption of 2,300 kcal in the form of Huel powder could reach the upper limit for a safe iron intake and potentially consume too much. As a result, some people, especially those with hemochromatosis, may have legitimate concerns that Huel’s high iron content could be dangerous in the long run. How can we be sure that Hueligans are not at risk of iron poisoning?

The safety limit is based on a mixed diet and therefore does not take sufficient account of the pronounced effects of antinutrients. Therefore, concerns about not getting enough iron might just as well be justified. How can we be sure that iron intake is adequate and not inhibited by phytic acid so that Hueligans are not at risk of iron deficiency anemia?

The amount of phytic acid from oats and flaxseed in Huel Powder v3.0 is around 310 mg per 100 g. Without the influence of other factors, this would significantly reduce the amount of iron actually absorbed and available to the body.

The data from Hurrell et al. (2010), in extreme cases, Hueligans would only take up 5% of the iron in Huel [4] , i. H. 1.9 to 2.0 mg per day (based on regular Huel Powder or Huel Black Edition in the amount of 2,000 kcal). Let us compare this with someone who consumes the NRV amount of 14 mg per day as part of a mixed, non-vegetarian diet: The iron intake of this person would be around 2, with the maximum absorption rate of 18% of the iron supplied [4] 5 mg lie. The difference is obviously very small.

It was found that the effect of phytic acid on iron absorption is dose-dependent [4] , with the intake from mixed meals with certain ascorbic acid-containing vegetables being significantly higher [4, 24] . Considering that Huel products contain higher amounts of ascorbic acid (300 mg per 2,000 kcal) than most ascorbic acid-rich vegetables, iron absorption from a Huel meal is at an optimal level.

This shows that the effects of vitamin C adequately compensates for the negative effects of phytic acid and that Huel products provide an optimal amount of iron for absorption.


  • Huel powders have a high iron content of 40 mg per 2,000 kcal or 8 mg per 400 kcal. For Huel Hot & Savory and Huel Ready-to-drink, it is 4 mg and 5 mg per meal, respectively.
  • Huel products are high in phytic acid, which could significantly reduce the bioavailability of iron.
  • Calcium has a slight inhibitory effect on iron absorption.
  • Huel products are abundant in vitamin C, which effectively increases iron absorption.
  • Considering all the factors that inhibit or increase iron absorption, the amount of iron in Huel products is optimal.


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