Due to human and animal research, a variety of nutritional and botanical substances (e.g., adaptogenic herbs, ascorbic acid, vitamin B1 and B6, coenzyme forms of vitamin B5 and B12, amino acid tyrosine and many more) appear to allow individuals to sustain adaptive responses that could minimize some systemic effects of stress. Systemic effects of stress may include an increase level of stress hormones such as cortisol, certain aspects of immune system function declining such as natural killer cell cytotoxicity or secretory-IgA and gastrointestinal microflora balance disruption.
Kelly GS. Nutritional and botanical interventions to assist with the adaptation to stress. Altern Med Rev. 1999 Aug;4(4):249-65. PMID: 10468649