Folic acid and hair loss
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Folic Acid Deficiency and Hair Loss
Research shows a clear link between folic acid deficiency and hair loss in both humans and animals. Folic acid is essential for cellular turnover, including in hair follicles, and its deficiency can lead to hair loss or alopecia. In a study on a Charolais calf with progressive hair loss, daily folic acid supplementation led to the disappearance of skin lesions and full hair regrowth within two months, highlighting the importance of folic acid for healthy hair growth . Similarly, animal studies in rats have shown that diets lacking folic acid result in hair loss, which can be reversed with folic acid supplementation .
Folic Acid and Hair Loss After Bariatric Surgery
Hair loss is a common complication after metabolic and bariatric surgery (MBS), with studies reporting an incidence as high as 57% to 77% in patients post-surgery 236. Low serum folic acid levels are consistently associated with increased risk of hair loss after these procedures 236. In particular, women and those with lower preoperative folic acid levels are at higher risk 23. While some patients try self-prescribed supplements, satisfaction with these interventions is low, suggesting that professional guidance and monitoring of folic acid and other micronutrients are important for prevention and management 36.
Folic Acid and Androgenic Alopecia
In men with androgenic alopecia (AGA), studies have found that most patients have deficiencies in several micronutrients, including folic acid 59. Personalized supplementation to correct folic acid deficiency, alongside other vitamins and minerals, has been shown to improve hair growth parameters, such as increasing the proportion of growing (anagen) hairs . However, while folic acid deficiency is common in AGA, the direct rate of hair loss may not always correlate with folic acid levels alone, suggesting a multifactorial cause .
Gender Differences in Folic Acid and Hair Loss
Some studies indicate that the relationship between folic acid and hair loss may differ by gender. For example, one study found that folic acid, zinc, vitamin B12, and thyroid-stimulating hormone levels correlated with alopecia in males but not in females, while iron and ferritin were significant in both genders . Another study in women with chronic diffuse hair loss found that folic acid levels were generally within the normal range, and other factors like ferritin and cobalamin (vitamin B12) were more predictive of hair loss .
Protective Role of Folic Acid Against Hair Cell Loss
Experimental research in zebrafish embryos exposed to ethanol (a model for fetal alcohol syndrome) demonstrated that folic acid supplementation can partially protect against hair cell loss, although retinoic acid was more effective . This suggests that folic acid may help prevent certain types of hair cell damage, especially when deficiency or toxic exposures are involved.
Conclusion
Folic acid plays a significant role in hair health, with deficiency linked to various forms of hair loss, especially after bariatric surgery and in some cases of alopecia. Supplementation can promote hair regrowth in deficiency-related cases, but the effectiveness may vary depending on the underlying cause and individual factors such as gender. Monitoring and correcting folic acid levels, particularly in at-risk populations, is a practical approach to managing and potentially preventing hair loss.
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