Greying Hair is a naturally occurring phenomenon that inevitably happens to all of us at one point or another, preferably later than sooner, but what exactly causes grey hair and can it be stopped once it starts?

The answer depends greatly on many factors, nutritional deficiencies, genetic predisposition and of course, aging! Lets take a closer look at a hair follicle. As you can see from the photo below, a hair follicle is made up of keratin in three layers - cuticle, cortex and medulla.

The cuticle is a set of tightly woven, overlapping scales that encapsulates the cortex and medulla. This is the part of the hair shaft that can be manipulated by styling products.

The second part is the cortex. This part represents the majority of the hair shaft. Pigments cells are what gives you your unique hair color and these are found throughout the cortex and medulla. The cortex also houses melanin, also known as color pigment.

There are two types of melanin: dark (eumelanin) and light (phaeomelanin). Melanin is distributed to hair follicles by cells called melanocytes. The formation of color begins before birth and depending on genetics, amount of either types of melanin and the distribution of it, all together they blend to create one unique hair color.

Age naturally reduces the amount of melanin injected into the hair shaft, decreasing the color hue until eventually it turns grey. For some, this process can happen very quickly while others remain grey-less for years.

There also health conditions that cause one's hair to grey prematurely such as B-12 deficiency and thyroid disorders. Vitamin B-12 deficiency reduces the production of melanin. It is important to not that even though you may accurately test negative for this condition, it is still possible for B-12 to be the culprit through malabsorption.

If you suspect your hair is turning grey for unknown reasons other then natural aging, seek medical advice.

From personal experience, I do have premature greying, but only since giving birth to my fourth baby. During this pregnancy, I was lacking in Vitamin B-12 and Iron and required many visits to the doctor for regular shots. This threw my body into a whirlwind and because of this, I suffered classic symptoms, which included grey hair. Now 2 years later, I have recovered, but the grey hair remains. Once grey, always grey. The follicle is dead of melanin, however, by making sure to get adequate nutrition, you can keep colored hairs you do have intact for a bit longer.