Although not usually considered a health problem it can be incredibly distressing, even if it is quite mild, as I know from personal experience. A number of years ago I had slight hair thinning which I was able to resolve by tackling some nutritional deficiencies. Here are some things to consider if you want to take action:
Could it be androgenic alopoecia?
Androgenic alopoecia occurs in both men and women and in men is often known as male pattern baldness. It is hair loss that is due to an underlying susceptibility of hair follicles to shrinkage under the influence of androgens (testosterone related sex hormones). It is one of the most common causes of hair loss and affects up to 7 in 10 men and 4 in 10 women at some point in their life. In men, hairline recession at the temples and balding of the crown occurs. In women the hair normally thins evenly over the top of their scalps. Female hair thinning at or after menopause can be related to an increasing dominance of testosterone-related hormones once oestrogen levels have declined. This is why women in later age often develop deeper voices or increased facial hair growth along with head hair thinning.
The commonest cause of androgenic alopoecia is the build up of a substance called DHT (dihydrotestosterone), commonly called “bad testosterone”. Some people are born with a genetic profile that means that their hair follicles contain DHT receptors. It is the presence or absence of this genetic factor and the presence of these DHT receptors that makes some people and not others susceptible to androgenic alopoecia. You can actually request a dihydrotestosterone test (along with other tests mentioned later in this article) from your GP, who should be familiar with it.
Taking measures to control or reduce DHT production can help slow progression of hair loss, and allow the balance of hair growth versus hair loss to re-establish itself. Therefore, by decreasing the level of DHT build up, you increase the chance of maintaining your hair count as well restoring lost hair and thickness. A number of foods are now known to contain substances that inhibit the enzyme that causes the production of DHT. Beta sitosterol in pumpkin seeds, catechins in green tea, and isoflavones in fermented soya products such as miso are some examples. Other foods such as pulses, rye and ground flaxseeds can have a similar effect.
Do you have good blood glucose control?
Several studies suggests that hair loss, and in particular androgenic alopoecia can be made worse by insulin resistance (pre-diabetes)  . Insulin resistance is where your body cells lose the ability to respond normally to insulin, the hormone that lowers blood glucose levels. Diets high in refined foods, soft drinks, heated vegetable oils or excessive saturated fats contribute to insulin resistance. Not eating enough foods rich in magnesium, chromium, vitamin B3 and zinc, being sedentary or taking statin drugs are other causes of insulin resistance.
What about patchy baldness (alopoecia areata)?
Alopoecia areata can sometimes be caused by coeliac disease and may be completely reversed by a gluten-free diet  . 4 out of 5 people with coeliac disease have no digestive symptoms and many test negative in the commonly –offered coeliac tests. For more information on coeliac disease and testing see the coeliac section on this website. Ireland has the highest rate of coeliac disease in the world, at 1 in 40 but as this genetic condition is grossly under-diagnosed, the true figure is likely to be higher. Average age of diagnosis of coeliac disease is over 50, partly because most people have no digestive symptoms and partly because until the condition reaches its end point the 2 common blood tests and biopsy results are likely to be negative.
What about Chronic Telogen Effluvium (CTE) and iron levels?
Chronic telogen effluvium is another common form of hair loss especially in women age 18 to 50. CTE is where the hair loss is evenly distributed across the head instead of just at the top of the head. Often its only the sufferer who notices that their hair is shedding more than it used to, or that their parting is getting wider. Tests often show that women with CTE suffer from lowered iron reserves (ferritin) in the body.
Did you know that there are two forms of iron in your blood? One form of iron is found in haemoglobin, which carries oxygen around the body in the blood. The other form of iron is in ferritin, an iron storing protein found in various organs, bone marrow and blood. Ferritin is important for hair thickness. This means your doctor needs to measure not just haemoglobin but also ferritin. Vitamin B12, which is another common test available through GPs, is needed for iron utilisation in the body.
If you are a woman with menorrhagia (heavy periods), iron stores will become depleted. Ironically, low iron levels can cause heavy periods. Sometimes women are put on oral contraception or given a coil to reduce flow. But either of these can lower your thyroid function as well as pose variety of health risks which many do not consider acceptable. Ironically, low thyroid function can cause hair to thin (see section on thyroid function below).
Do you get enough nutrients to help you use iron properly?
Did you know you need at least 6 other nutrients for iron to work correctly in the body? If you are low in vitamin B2, B5, B12, folic acid or manganese then a functional iron deficiency results. This means that even if enough iron is present, you can’t use it properly. If you regularly don’t eat vitamin C rich foods (raw fruits and raw or only lightly cooked veg) then iron is less well absorbed in your gut. Deficiency can also be caused by regularly eating foods that bind to iron in the intestine, making it impossible to absorb. Tannins (in tea) are one example of iron-binding substances that should not be consumed within a couple of hours of a meal. Copper deficiency can impair iron absorption but excess copper causes functional iron deficiency. The balance of nutrients in your body needs to be right.
Could your thyroid function be compromised?
Thinning hair is one of numerous symptoms that you can experience if your thyroid function is impaired. I have met many patients on thyroid medication and many more whose blood tests are normal but who display classic signs of hypothyroidism, including lowered basal body temperature, loss of the outer third of the eyebrows, or excessive fatigue not related to anaemia. A patient may be producing adequate levels of T3 (tri-iodothyronine), the active thyroid hormone, but may have hormone resistance at cellular level. This means the cells can’t respond to the hormone.
Thyroid hormone resistance is usually due to deficiency of essential fats, low intake of potassium foods (vegetables and fruit) or a very sedentary lifestyle. Medications can also play a part in suppressing thyroid function. Most drugs deplete some vitamins and minerals. Stomach acid inhibitors (eg losec) are a classic example as they interfere with the ability to digest all minerals. With chronic use patients end up deficient in the zinc, iron, selenium, iodine and manganese they need for good thyroid function. In Ireland fluoride from drinking tap water further suppresses iodine in the body – iodine is one of the components of thyroid hormone. If you drink the recommended 2 Litres of water a day from Irish taps you will be taking in 5-7mg of fluoride a day. To suppress overactive thyroid (hyperthyroidism) doctors used to use 3-7mg of fluoride as a daily dose as they knew it impaired function.
Are you digesting your food properly?
If you have digestive problems then you could be eating a perfect diet with lots of hair-building nutrients and not get the benefits. If there are digestive issues these most be resolved in order to be able to get back to having a full healthy head of hair. Please refer to the digestive topics on this site.
Are you vegetarian or pescatarian?
If you eat little or no meat, your body will be low in an amino acid called L-lysine. Lysine is needed for iron utilisation. Vegetarians often rely on very high intake of dairy foods (eg. cheese) which impairs the absorption of iron if eaten at the same meal.
Are you under pressure?
Bereavement, family conflict, job insecurity, continuously multi-tasking or needing to be busy all the time – all are signs that you are likely to be stressed. The triggers for stress vary hugely from person to person. Chronic stress means that your body is constantly in fight-or-flight mode and therefore non-emergency functions in the body take a back seat. Digestion is often one of the first things to be compromised. Any good nutritional coaching programme will assess your stress levels. If appropriate, your nutritionist will then suggest stress-busting techniques and advise on how to get more relaxing nutrients such as magnesium into the diet. When you are stressed you use up hair-building nutrients more quickly. These include vitamin B5, zinc, vitamin C, selenium and manganese.
Could you have a chronic infection?
Fungal infections on the scalp can cause hair loss. If you have fungal infections elsewhere (eg on a nail) it could be a clue to look for infection on the scalp. A healthy immune system will see off infections, including on the scalp. Enhancing immune status can be helpful, combined with strategies to eradicate the infectious agent. Another thing to consider might be a chronic bacterial infection, which can cause ferritin levels in the blood to decline. This happens because the body cleverly tries to move iron away from the reach of iron-loving bacteria in the blood. This can then compromise hair thickness.
 Matilainena, V et al (2000) Early androgenetic alopecia as a marker of insulin resistance.
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 Matilainena, V et al (2003)Hair Loss, Insulin Resistance, and Heredity in Middle-aged Women. a Population-based Study. Journal of Preventive Cardiology vol. 10 no. 3 227-231
 Corazza GR et al (1995) Gastroenterology. Oct;109(4):1333-7. Celiac disease and alopecia areata: report of a new association.
 Fessatou S, Kostaki M et al (2003) Coeliac disease and alopecia areata in childhood. J Paediatr Child Health. 2003 Mar;39(2):152-4.