Brittle or Thinning Hair? This Could Be Why!

thinning hair

Iron’s Connection To Thinning Hair

Iron Physiology 101

Most of us know that low iron makes you tired. This is because you have to have iron in order to make enough hemoglobin, which is the part of your red blood cells that binds and transports oxygen. There are several forms of anemia, but one of the most common is iron deficiency anemia. Low iron levels lead to less oxygen, which leads to exhaustion. 

There are several steps in the iron pathway before red blood cell count and size begins to decline, indicative of full-blown anemia. Ferritin (the storage form of iron) can be an early indication of a problem. 

The Connection Between Iron Levels and Hair

Your hair follicles store ferritin (it helps to produce hair cell protein). When your body is short on iron for its essential functions (such as red blood cell production), it will steal it from the ferritin stored in less essential parts of the body, such as the hair follicle. 

If your ferritin levels are sufficient, a single hair grows five years on average before falling out and being replaced. If it’s insufficient, this life cycle gets shorter, leaving you with thinning hair. Low ferritin also affects the hair’s ability to grow, and may change the hair’s texture, rendering it weaker, more brittle, leaving it easily damaged from washing, drying and styling.

The Connection Between Iron and Your Thyroid

Another major cause of hair loss is hypothyroidism. Iron is one of the key nutrients required for conversion of T4 (inactive thyroid hormone produced by the thyroid) to T3 (active thyroid), and iron deficiency increases the body’s tendency to produce more of the inactive reverse T3, rather than the active T3 hormone. 

What this means is that it’s possible for someone with low ferritin to have hypothyroid symptoms (complete with thinning hair) and yet appear “normal” according to the standard TSH and T4 thyroid labs.

What Causes Iron Deficiency

  • Decreased absorption and depletion: This can occur with proton pump inhibitors such as omeprazole, as well as prolonged ingestion of aspirin or NSAIDs. It can also occur with ingestion of too much coffee, black tea, manganese, fiber, calcium, magnesium, or phosphates (soda). This is why, if you take an iron supplement, it’s important to do so on an empty stomach.
  • A hidden bleed: It’s always worth checking for this. Hidden bleeds often show up in the GI tract, and screening could include a stool culture, colonoscopy, and/or an endoscopy.
  • Menstruation: Menses = iron loss, which means menstruating women are more likely to be at risk for ferritin-related hair loss. Women who bleed heavily are at even higher risk; if this is you, you’ll need to get your estrogen-to-progesterone ratio balanced as well.
  • SIBO (Small Intestinal Bacterial Overgrowth): Overgrowth of gut flora in the intestines can also rob your body of iron, as certain bacteria use iron in their life cycles.

Adequate Ferritin Levels

Ferritin levels are considered normal for women between 10-120 ng/mL, and between 30-250 ng/mL for men. However, about 50-70 ng/mL are required to stop hair loss and for adequate hair regrowth. 

Iron in Food

Iron deficiency is very common in people who eat vegetarian or vegan diets. Although iron can be found in plant-based foods such as nuts, raisins, prunes, and whole grains, it’s difficult to eat enough of these to achieve adequate iron intake, compared to usual portion sizes and iron concentrations in meat and poultry.

Some of the best sources for iron are wild caught seafood, pastured poultry or grass fed beef, especially in the form of liver or spleen.  Spleen is actually about 5 times richer in iron than liver.  But if you’re not a big lover of beef spleen (can’t blame you) you can always take it in supplement form.  When you take it (or eat it) in whole food form, it contains all the important co-factors you’ll need for absorption. 

However, when eating meat I always advocate choosing free range, pastured or grass fed (grass finished when possible) meat sources over industrially raised and fed meats.

Should You Supplement With Iron?

While a low dose, whole food iron supplement could be helpful, it’s best not to go on a hard core regime unless you’ve been tested and are shown to have low levels. Iron is one of those nutrients for which too much can be as bad as too little. Iron is relatively hard to absorb, so it helps if it’s given on an empty stomach in a non-constipating chelated form, along with certain other nutrients like Vitamin C that will aid in its absorption. However, as I mentioned previously, I believe the very best supplement will always be in the form of desiccated organ meats (like this one) which are from properly raised, grass fed animals.

Be patient! It can take at least a few months and sometimes up to a year with ferritin at adequate levels before you are likely to see significant hair regrowth. Remember to have your ferritin levels re-checked in about 3 months. 


While you’re working on the health of your hair from the inside, it’s important that you not continue to use products or styling methods that will make the breakage worse. Here are a few tips that can help prevent further damage:

  1. Wash your hair a little less often. If you’re used to daily washing, try every other day, and use a good dry shampoo on the day in between. (I like this one!) If you don’t like dry shampoo, try a good hat! 🙂
  2. When you do wash your hair, use a shampoo and conditioner that’s gentle and has fewer harsh chemicals. One brand I’ve fallen in love with is Shea Moisture. I have two favorite varieties that are excellent with brittle hair. One is the Strengthen and Restore which includes Jamaican Black Castor Oil for new growth! The second is their Yucca and Plantain Anti-breakage Strengthening formula. Truthfully, I switch back and forth between the two regularly.
  3. Use gentler styling methods. Instead of drying your hair daily, let it dry naturally. Or if you still use a hairdryer, lower the heat setting! Maybe just go with nice little waves and avoid the flat iron. Or, hey, there’s always that hat idea again!? Personally I’m a fan of the ponytail.
  4. Try a detangling brush like this one has made a huge difference for me! In fact it made such a difference I ended up  getting one for my entire family as a Christmas gift. The theory is that hair is weakest when wet and pulling at it can snap it like a rubber band. A good detangling brush is key to gently loosening knots without pulling or breaking hair (especially if it’s already brittle).

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