Background:Nutritional deficiencies are known to be associated with hair loss; however, the exact prevalence is not known.Aims:The aim of this study is to evaluate the prevalence of nutritional deficiencies in participants with hair loss.Materials and Methods:In this cross-sectional study, 100 enrolled participants were divided into telogen effluvium (TE), male-pattern hair loss (MPHL), and female-pattern hair loss (FPHL) based on the type of hair loss. All participants underwent laboratory estimation for micronutrients and amino acid levels.Results:Participants with hair loss showed varied amino acid and micronutrient deficiencies across all types of hair loss. Nutritional status did not vary much between the types of hair loss. Among the essential amino acids, histidine deficiency was seen in >90% of participants with androgenic alopecia and 77.78% of participants with TE while leucine deficiency was seen 98.15% of participants with TE and 100% with FPHL. Valine deficiency was also very common across alopecia subtypes. Among the nonessential amino acids, alanine deficiency was observed in 91.67% FPHL, 91.18% MPHL, and 90.74% TE. Cysteine deficiency was present in 55.58% and 50% of participants with MPHL and TE, respectively. A relatively higher proportion of participants with TE had iron deficiency compared to androgenic alopecia (P = 0.069). Zinc deficiency was seen in 11.76% of participants with MPHL while copper deficiency was seen in 29.41% and 31.48% of participants with MPHL and TE, respectively.Conclusion:Nutritional deficiency is a common problem in participants with hair loss irrespective of the type of alopecia. The findings of our study suggest need for identification and correction of nutritional deficiencies in patients with hair loss.