Nutritional deficiencies may hasten hair greying, scientists suggest
The loss of pigment that turns hair grey is driven largely by genetics and the natural ageing of melanocytes, the cells responsible for colour in hair follicles. But emerging evidence points to nutritional shortfalls as a potential accelerant for some people, according to Dr Ayesha Bryant, an associate professor of medicine at the University of Alabama at Birmingham and a clinical advisor at Alpas Wellness.
Scientists have found “strong evidence suggesting several nutritional and biochemical factors can potentially accelerate the onset or progression of hair greying in some individuals,” Dr Bryant told GB News. The strongest scientific link exists between premature greying and deficiencies in vitamins B12 and D, iron, and copper, with folate showing a slightly weaker association.
The role of specific vitamins and minerals
Vitamin B12 is central because it is crucial for DNA synthesis and cellular renewal within melanocytes. The UK recommended daily intake for adults aged 19 to 64 is about 1.5 micrograms (µg). Primary dietary sources include meat, fish, dairy and eggs, meaning vegans and vegetarians face a higher risk of deficiency. Supplement labels often list much higher amounts — 500 to 1,000 µg — due to variable absorption. People over 50 may need supplements because absorption decreases with age, and the Vegan Society recommends at least 10 µg daily for vegans.
“According to at least two studies, a deficiency in these nutrients was associated with earlier onset of hair greying, particularly if they were also experiencing anaemia,” Dr Bryant said, specifically linking B12 and folate to this finding.
Folate, or vitamin B9, also plays a role in DNA synthesis. UK adults need 200 µg per day, with pregnant women advised to take a 400 µg supplement until 12 weeks of pregnancy. Rich sources include leafy green vegetables, peas, chickpeas, kidney beans, fortified breakfast cereals and liver. Since folate is water-soluble and can be lost during cooking, steaming or microwaving is recommended. A daily intake of 1 mg of folic acid from supplements is considered a safe upper limit in the UK, partly because higher doses can mask a vitamin B12 deficiency.
Vitamin D, essential for calcium absorption and bone health, is also linked to hair colour. The UK recommends 10 µg (400 IU) daily for most adults and children over one year, including pregnant and breastfeeding women. Oily fish, egg yolks and fortified foods such as breakfast cereals and fat spreads provide vitamin D, but dietary intake alone is often insufficient. The UK government advises everyone to consider a daily supplement during autumn and winter, from October to March, because of inadequate sunlight. Individuals with darker skin tones, limited sun exposure or certain medical conditions may require year-round supplementation.
Iron is vital for red blood cell formation and oxygen transport. The UK recommends 8.7 mg per day for men and postmenopausal women, and 14.8 mg per day for premenopausal women, with higher requirements during pregnancy. Red meat, offal, fish, poultry, beans, lentils, chickpeas, nuts, seeds, dried fruit and fortified breakfast cereals are all sources. Fortified cereals and breads contribute significantly to iron intake in the UK. Absorption of non-haem iron from plant sources is enhanced by vitamin C but inhibited by tea and coffee consumed around mealtimes. Half of all women in the UK do not consume the recommended nutrient intake for iron, and vegetarians and vegans are at higher risk of deficiency.
Copper, a trace element, acts as a cofactor for the enzyme tyrosinase, which is essential for melanin production. UK adults need 1.2 mg per day. Shellfish, liver, fish such as trout and salmon, beans, cocoa powder, whole grains, avocados, almonds and sunflower seeds provide copper. Over a third of UK copper intake comes from cereals. Women in the UK are reported to fall short of the target copper intake.
Dr Bryant noted that insufficient copper levels may diminish the body’s capacity to produce hair pigment effectively. “A number of case studies and smaller-scale studies report some level of repigmentation in areas where a person had previously lost pigment, such as around the eyes and eyebrows, after a deficiency in vitamin B12 was addressed,” she said.
However, she cautioned against expecting dramatic results from supplements alone. “For the vast majority of individuals, supplementing will not provide full reversal of genetically-driven greying, and supplements may only address a contributing factor of genetically-programmed greying and not the primary reason for greying.”
Genetics remain the primary driver
Despite the nutritional links, Dr Bryant emphasised that “hair greying is largely determined by genetics and by the normal ageing of melanocytes.” The natural ageing process of these pigment-producing cells is the principal cause, and nutritional deficiencies are best understood as a trigger that can accelerate an already-programmed timeline in some people.
Only when the underlying cause is reversible — for example, a confirmed vitamin B12 deficiency that is corrected — does supplementation stand a chance of slowing or partially reversing greying. Even then, Dr Bryant said, the effect tends to be modest and limited to specific areas, not a full restoration of colour across the whole head.
Lifestyle factors and oxidative stress
Beyond nutrition and genetics, lifestyle choices also influence follicular health. Dr Bryant warned that “chronic stress, smoking, and poor sleep are associated with greater oxidative stress and therefore may increase the rate of ageing of follicles.” Oxidative stress is believed to damage melanocytes and accelerate pigment loss. Scientists continue investigating how this process works, and research into preventing greying once genetic programming has begun remains at an early stage.
Dr Bryant recommended a balanced diet to support healthy pigmentation, focusing on adequate protein alongside iron-rich foods such as legumes and red meat. Leafy green vegetables, eggs and legumes provide essential B vitamins, while nuts and shellfish offer valuable copper. She stressed that these dietary measures are best viewed as part of overall health maintenance, not a cure for greying hair.