Thursday, November 26, 2015

Ferritin (Iron), Vitamin D and Hair Shedding

I provide my sources via in-text citations and in the references at the end. This information does not replace medical consultation or blood tests. Consultation with a doctor or nurse practitioner or pharmacist should be sought for diagnosing and treating nutrient deficiencies. If you have no health insurance or your insurance does not cover diagnostic testing (which includes testing for nutrient deficiencies), ask at your local clinic or pharmacy about on-demand testing or independent lab testing, but please plan supplements with the guidance of a qualified physician or pharmacist.


In pre-menopausal women, low serum (blood) ferritin is one of the more common causes of hair thinning or pattern hair loss. ©Science-y Hair Blog 2015

When you get a typical blood test - the iron test is often for hemoglobin. That is the form of iron in your blood that can carry oxygen to your tissues. If it is low, you are anemic. If you are anemic - your hair may be thinning. But recently, researchers have questioned how low is truly a"low" level for ferritin in relation to syndromes like thinning hair and female pattern hair loss and restless legs syndrome. Ferritin is a form of iron that is stored in your liver - like a "bank" of iron from which your body makes withdrawals when it needs iron. We use iron for a lot of processes in our bodies. If you think of your body like a machine made from lots of different materials - including metals - then naturally there's going to be some iron here and there and in a lot of places, playing a lot of roles. Carrying oxygen is only one of iron's roles in your body.

If your ferritin is low, you don't have the back-up supply or iron you need. You can shuttle oxygen around, but other functions suffer. Like hair growth.

How much ferritin is enough? The level that will be flagged as low on a blood test is around 10 ug/l  (that's micrograms per liter). But studies of hair loss or thinning indicate that ferritin levels need to be above 40-50 ug/l (Rasheed et al.) or up to 70 ug/l (Rushton, Song et al.) to prevent iron-related hair loss. For women, ferritin levels up to 300 ug/l are still within the normal range, so 70 ug/l doesn't appear to be an excessive target.

What does that mean for you? If you see a doctor for hair loss, ask to have your ferritin tested as well. If it is lower than 40-70 ug/l, discuss a reasonable strategy for getting your ferritin level up above 40-70 ug/l. Closer to 70 seems to be indicated at the cut-off point above which hair loss can't be called iron-related (people without hair loss have levels that high or higher, but more women with hair loss have low ferritin levels).©Science-y Hair Blog 2015

Iron supplements are the usual treatment, but they can be dangerous, even deadly, so a blood test is necessary and so is follow-up re-testing to see how the supplement is working. Iron supplements can also be difficult to take, with common side effects being nausea, stomach pain, and constipation. To avoid nausea, take the supplement with food. To avoid constipation, magnesium citrate supplements or stool softeners are common remedies. Taking iron with vitamin C can increase your absorption of iron up to 100%. 250 mg of vitamin C provides the greatest boost in iron absorption (Cook and Reddy).©Science-y Hair Blog 2015

Coffee, high-calcium foods (dairy products) and foods high in phytate (beans, whole grains) all interfere with iron absorption - avoid eating/drinking those at the same time as you take an iron supplement if possible.©Science-y Hair Blog 2015


Low vitamin D levels have also recently been associated with thinning hair and female pattern hair loss. Low vitamin D is becoming more common as people spend less time outdoors, and wear sunscreen and protective clothing. A study by Rasheed et al found a vitamin D level below 30 nmol/liter (nanomoles per liter) which is the same as 12 ng/l (nanograms per liter) was associated with thinning hair or female pattern hair loss. This level is also considered a serious deficiency in vitamin D.

Vitamin D levels need to be above 67 nmol/l (27 ng/ml) to no longer be associated with thinning hair. The National Institute of Health (NIH) indicates that a level of 50 nmol/l or greater (20 ng/ml) is adequate for most healthy adults, so that seems a reasonable target for women with hair thinning or hair loss.©Science-y Hair Blog 2015

Vitamin D comes from the sun, getting enough sunlight on your face and arms or legs or back a few times per week can be all it takes to get enough - it takes only a few minutes. In many quite Northern (or Southern in the Southern Hemisphere) latitudes, you really don't get vitamin D from the sun in winter, even if you are a fan of bikini ice fishing (I sincerely hope that's not a real thing). If you can correlate your latitude in line with any of these cities, you can calculate your UV exposure to get enough vitamin D:

There are many food sources of vitamin D also, see this page for sources - this is from the Skin Cancer Foundation, who don't want us over-exposed to the sun:

Vitamin D can also can and should be checked by a blood test, especially if you plan to take supplements because vitamin D supplements can also be toxic in too-large doses over time.  For people taking supplements, talk with a pharmacist  about a safe amount to supplement (stop in when they're not too busy - they're very knowledgeable). It is possible to over-supplement with natural vitamin D sources like cod liver oil, so it's best to plan supplementation carefully if you use natural sources also.©Science-y Hair Blog 2015

People over the age of 50 cannot synthesize vitamin D from the sun as well as before age 50 and may need supplements to stay in the "normal" zone - which is important in maintaining muscle and bone health and for preventing falls. If you're in this age group - pay attention to your vitamin D levels when you have a medical check-up. Ask to have your Vitamin D levels tested if that is not routinely done.

Bottom line:
To prevent iron-related hair thinning, have your blood ferritin levels tested and maintain a level around 70 ug/l, assuming you are healthy and your physician approves. This is higher than the level that a laboratory will label as a deficiency which is 10 ug/l or below.  The clinical "low" it too low for hair-maintaining purposes.©Science-y Hair Blog 2015

If you donate blood regularly- get your ferritin checked! You lose a lot of iron with every blood donation. Women also lose large amounts of iron during childbirth. Surgery or injury with significant blood-loss may deplete your ferritin stores.

To prevent vitamin D deficiency-related hair thinning, it may be helpful to keep vitamin D levels well in the normal range for healthy adults, 20-50 ng/ml (~50-70 nmol/l), though the study cited indicates that hair loss is less likely toward the higher end of that range.


Decreased Serum Ferritin and Alopecia in Women. Journal of Investigative Dermatology 2003
D Hugh Rushton

Effect of ascorbic acid intake on nonheme-iron absorption from a complete diet. American Society for Clinical Nutrition 2001, 93-98
Cook JD, Reddy MB

Iron Plays a Certain Role in Patterned Hair Loss. Journal of Korean Medical Science 2013, 934-938
Song Youn Park, Se Young Na,Jun Hwan Kim, Soyun Cho, Jong Hee Lee

Serum ferritin and vitamin d in female hair loss: do they play a role? Skin Pharmacology and Physiology 2013, 101-107
Rasheed H, Hahgoub D, Hegazy R., El-Komy M, Abdel Hay R, Hamid MA, Hamdy E.


  1. Hello! I just found your blog and I love it. It is great to see some real scientific info and advice vs. blogger hearsay, hype, and group-think. I have an issue that I hope you could point me in the right direction to solve. I basically have thick wavy hair, but the problem is that the waves aren't symmetrical, or appealing in the least. Just a rat's nest. It tends to look better when it is drier and in drier climates (less frizz and waves). Everything out there seems to push moisturizing properties, but humidity makes my hair worse. I have recently resorted to using some sort of goop (tried a lot of things more or less with similar results) and a blow drier, which makes my hair pretty much perfect, but when it is humid, or rains it is a rat's nest again despite using silicone based products, or products with other occlusive ingredients. One thing is certain, humidity and my hair are enemies, but other than shaving my head I don't know what I can do and I worry about damage using the blow drier, which could make the humid days worse for my hair. Any direction would be much appreciated.

    1. For humid and rainy weather, the solution is to use a product with some firm hold - with ingredients like PVP or PVA/VP Copolymer or with the words "acrylates copolymer." Polyquaternium-4 and Polyquaternium-69 are also good with humidity-resistance. Occlusives are helpful, but "hold" is what glues the hairs together so they don't seek their own orbit in high humidity. If you're using a blow dryer, keep it on low heat and put a diffuser attachment (looks like a bowl with fingers in it) on the end to spread the heat out. As long as the temperature is below 120°F, your hair will probably be okay.
      Some of the finishing products (waxes, puttys, pastes) have some of the "hold" ingredients listed above in them and will provide an extra layer of protection in humidity.
      Don't fear moisture in hair products - usually that refers to conditioners. You do need conditioner to add weight, lubrication and keep hairs flexible. Humectants in products are great too (or at least some of them) - keeping hair hydrated on the inside keeps the waves lined up better. Hydrated hair is more flexible and flexible hair tends to have a more-defined wave. It's the hyper-hydration of humidity that is a problem.
      If you're worried about heat damage from blow-drying, click on the tab in this blog "products by ingredient category" and scroll down to the heat protectants. There are sprays, creams and gels with laboratory-proven heat protectant ingredients. Quite a few well-formulated products in a variety of price ranges. Good luck!

  2. Thanks for your advice. I have some mousses that have these copolymers in them and they are great when it isn't humid, but the still seem to miss the mark in humid weather. Also, I notice that they tend to rinse out very easily so I was under the impression that they are fairly water soluble, which in my mind isn't good for humidity. I have this other product where the high on the list of ingredients is dimethicone, which is pretty darn occlusive, but alas no dice. I am curious about using powder type products, or dry shampoos to add texture and help with moisture, do you have any opinions on those? Thanks.

    1. Volumizing powders and dry shampoo have starches or clays (among other things) in them which create a little bit of friction in hair. With friction between strands, the hairs can't settle in tightly next to each other, so that creates or assists with volume. That might help in humidity for hair that tends to go flat on the scalp. It might reduce hair from frizzing in humidity a little bit.
      The best thing to combat humidity is to use stronger-hold products that contain one of the Polyquaternium ingredients or acrylates copolymer *as well as* PVP or PVA/VP. They're synergistic because the hold they provide is a bit different. And combine that with a product with occlusive ingredients (under the strong hold product or incorporated into it).
      Silicones alone are not always the best for humidity - silicones that are part of a creamy, leave-in conditioner or curl cream type of product benefit from the weight of the conditioning ingredients. SIlicones alone (such as a serum) don't quite have the weight to reduce frizz. Leave-in conditioners can give hair a bit more weight.
      Good luck!

  3. Thanks a bunch! Sorry for being a PITA, but do you know the difference between PV/VA Copolymer and PVA/VP copolymer? Also, are there ways of finding these ingredients you mentioned and making a product myself, or am I kidding myself?

    1. I often will do an internet search on the ingredient (in quotes) with the words "hair." Another trick is to go to EWG and do a search on the ingredient. At the left will be a list of links, including "products" to click. After products, click "hair care, styling" or gel or mousse as you're offered it. Popular products that are quite humidity-proof for curly/wavy hair are Jessicurl Spiralicious, Deva Curl Frizz Free Volumizing Foam, Ouidad Climate Control, Some of the Innersense products, John Frieda Curls (something) mousse.
      You can buy some of these ingredients from an assortment of suppliers (usually with $8+ shipping), and make your own products. But it takes a lot of trial and error and failed batches to get things right.
      Sometimes it's a matter of finding a product that "sticks" your hair together to hold it while drying and then has enough hold to keep it that way after you remove the crunch. That may mean a thicker product - or a thinner one. If it doesn't pull your hair together, it's unlikely to be very helpful when the humidity rises.

      All those variations on PVP/PVA copolymer are the same thing. If they throw in different letters (M, for example) or methacrylate - that's something else.