Low serum ferritin levels usually result from the loss of blood during menstruation, which is just enough to cause a gradual depletion of iron stores in the body. Additionally eating a diet containing little or no red meat is likely to give rise to a lower amount of available iron.
Research has shown that if the iron deficiency is corrected and the serum ferritin level is raised to a certain ‘trigger point’ then hair growth will resume. In fact, what actually happens is that the growing stage of the hair follicles is lengthened so, at any one time there are more hairs in the growing stage.
This means that hair volume will start to increase and any excessive shedding will reduce. However, this takes several months because ferritin levels can only be raised slowly. Also once the ‘trigger point’ is reached and hair growth starts, it takes 2 – 3 months for the shedding to reduce and another 3 – 6 months for the new hair to reach a length that contributes outwardly to fuller hair.
Whilst iron is usually the key factor, other nutrients also play an essential role. This was highlighted by research which showed that a significant proportion of women who were given an iron supplement failed to respond, even when given a high dose with additional vitamin C (which is known to help iron absorption).
This problem was overcome when it was realised that intake of the amino acid L-lysine was very low in many people’s diets, particularly those who eat little or no meat.
When L-lysine was added to the other nutrients being given, most women went on to reach the target ferritin level, and their hair volume subsequently increased. When they stopped the hair shedding resumed several months later.