Iron deficiency is one of the most common nutrient deficiencies worldwide, and one of the most overlooked reasons behind hair thinning, excessive shedding, and slow regrowth. While many people associate low iron with tiredness or pale skin, its impact on hair health is equally significant. Without enough iron, the body struggles to produce healthy red blood cells, which transport oxygen to the hair follicles. As oxygen supply drops, follicles weaken, growth slows, and hair begins to shed more than normal. According to a study published in the Journal of the American Academy of Dermatology, iron plays a key role in hair-follicle physiology and low iron is associated with increased hair shedding and disrupted growth cyclesWhy iron matters for hair healthIron plays a crucial role in producing haemoglobin, the protein in red blood cells responsible for carrying oxygen throughout the body. Hair follicles are highly active tissues that require a constant oxygen supply to grow strong, healthy strands.When iron levels fall, the body prioritises essential functions and diverts oxygen away from non-essential processes such as hair growth. As a result:Hair follicles shift prematurely from the growth phase (anagen) to the resting and shedding phase (telogen)Strands grow weaker, thinner, and fall out more easilyNew hair grows slowly or may not grow at all This condition is known as telogen effluvium, a common form of temporary hair loss triggered by nutrient deficiencies, stress, or illness.How iron deficiency causes hair lossIron plays a crucial role in keeping your hair strong, healthy, and growing properly. When your body lacks enough iron, it affects the nourishment and functioning of your hair follicles, leading to increased shedding and weaker strands. This is why iron deficiency is one of the common yet often overlooked causes of hair loss, especially among women. Here’s how low iron levels can directly impact your hair health.Reduced oxygen supply to hair folliclesLow iron means reduced haemoglobin and, therefore, reduced oxygen delivery. Hair follicles become undernourished, causing increased shedding and weaker hair structure.Impaired keratin productionKeratin, the protein that makes up your hair, requires iron for its synthesis. Insufficient iron results in fragile, brittle strands that break easily.Disruption of the hair growth cycleIron deficiency pushes hair into the shedding phase sooner than expected. If untreated, this leads to noticeable thinning over time, especially around the crown and hairline.Signs of iron deficiency-related hair lossHair loss from iron deficiency can appear subtly at first. Some common signs include:Excessive shedding: You may notice more hair on your pillow, in the shower, or when brushing.Thinning hair: Hair density decreases, particularly along the top of the scalp.Slow regrowth: Hair takes longer to grow back after shedding.Brittle strands: Hair may feel dry, break easily, and lose its natural shine.Along with hair symptoms, iron deficiency often presents with:FatigueWeaknessPale or dull skinCold hands and feetDizzinessShortness of breathBrittle nails or ridgesIf you experience hair loss along with these symptoms, iron deficiency could be the underlying cause.Who is most at riskIron deficiency can affect anyone, but some groups are more susceptible:Women of reproductive agePregnant womenVegetarians and vegansPeople with gut disordersIndividuals with heavy bleedingDisclaimer: This article is for informational purposes only and should not be considered medical advice. Please consult a healthcare professional before making any changes to your diet, medication, or lifestyle.Also read | Vitamin D may reduce heart attack risk: Study highlights cardiovascular benefits