Don't Ignore Gut Health When Trying to Raise Iron Levels

Many thyroid patients struggle to keep their iron levels up to a healthy level as a result of the effect of prolonged hypothyroidism.

The three main tests to use to determine if iron is adequate within the body are: serum iron, serum ferritin and transferrin saturation %.

From patient experience thyroid patients usually feel better if:
1. Serum iron is over 90 ug/dL and ideally closer to 100-110 ug/dL. This is based on a lab range of 65-176 ug/dL for men and 50-170 ug/dL for women.
2. Serum ferritin is in the range 70-90 ng/mL. This is based on a lab range of 22-320 ng/mL for men/post menopausal women and 10-290 ng/mL for pre menopausal women.
3. Transferrin saturation % in the 35-45% range.

This post is not about iron itself and about supplementing it to achieve healthy levels. It is about the digestive system and its role in absorbing iron and the implications of this.

The absorption of the majority of nutrients takes place in the jejunum (the middle section of the small intestine) the following notable exceptions:
a. Iron is absorbed in the duodenum and first part of the jejunum.
b. Vitamin B12 is absorbed in the terminal ileum (the last part of the small intestine).
c. Water and lipids are absorbed throughout the small intestine.
d. Sodium bicarbonate, glucose, fructose and amino acids are also absorbed in the small intestine.

The mechanism of iron transport from the gut into the blood stream remains a mystery despite intensive investigation.  The physical state of iron entering the duodenum greatly influences its absorption however.

Gastric acid lowers the pH in the duodenum, enhancing the solubility and uptake of iron. When gastric acid production is impaired (for instance by acid pump inhibitors such as the drug, prilosec), iron absorption is reduced substantially.

Heme is the name of a number of naturally occurring organic molecules that contain iron. Heme is found in meat. Interestingly, heme is absorbed by machinery completely different to that of inorganic iron. The process is more efficient and is independent of duodenal pH. Consequently meats are excellent nutrient sources of iron. Meat is the best form of food to obtain iron from as even when stomach acid is reduced, which it often is in hypothyroid patients the natural form of organic iron is still absorbed extremely well. Many people discuss the benefits of eating vegetables like spinach but this form of iron is not as well absorbed as the heme in meat (red meat, liver and kidneys especially). The shortage of meats in the diets of many of the people in the world adds to the burden of iron deficiency.

A number of dietary factors influence iron absorption. Ascorbate (as in vitamin C) and citrate increase iron uptake in part by acting as weak chelators to help to make the iron more soluble in the duodenum. Iron is readily transferred from these compounds into the mucosal lining cells. Conversely, iron absorption is inhibited by plant phytates and tannins. These compounds also chelate iron, but prevent its uptake by the absorption machinery. Phytates are prominent in wheat and some other cereals, while tannins are prevalent in (non-herbal) teas.

So, the health of the digestive system is critical to the raising and maintenance of good iron levels as it is the duodenum that absorbs iron. Low stomach acid may also affect the absorption or iron.

It is also important to note that all iron is not equal. Iron in meat is the most effectively absorbed. In addition to this for someone with a gut that is already compromised in some way then they often have a group of pathogenic bacteria growing in their gut. These pathogens are iron-loving bacteria and they consume much of any inorganic iron supplements that are taken, which in turn feeds the population and creates further imbalances in the gut flora. These bacteria include: Actinomyces spp., Mycobacterium spp., strains of E.coli, Cornybacterium spp., and others. Consequently, for someone with a compromised gut taking iron supplements may make this situation worse and particular attention may need to be given to healing the gut.

For people who struggle to raise their iron storage then infusions or injections may be needed from their doctor.

The bottom line is that iron is critical to the function of many of our systems including thyroid hormone action. Good iron levels are essential but we must not ignore the digestive system. Improving the health of a thyroid patient's digestive system may be critical to the absorption of iron and other nutrients as well as limiting the entry of other toxins into the bloodstream.

Best wishes,

Paul