Vitamin C (ascorbic acid), including its mixed forms, is scientifically recognized for its role in supporting the adrenal glands. The adrenal glands have one of the highest concentrations of vitamin C in the body and utilize it extensively, especially during the synthesis of steroid hormones such as cortisol. During periods of physical or psychological stress, vitamin C is rapidly depleted from the adrenal cortex, suggesting a functional requirement during stress adaptation.

Animal studies have consistently shown that vitamin C is crucial for normal adrenal function and hormone production. In humans, some clinical research indicates that vitamin C supplementation may help modulate the stress response by supporting adrenal hormone output and reducing cortisol levels after acute stress. For example, randomized controlled trials have shown that vitamin C can reduce blood pressure and subjective stress in response to stressors, which is thought to be partly due to a blunting of excessive adrenal cortisol secretion.

However, while the physiological connection between vitamin C and adrenal health is well-established, direct clinical evidence for routine supplementation to "support the adrenal glands" in healthy individuals remains limited. Most studies show benefits primarily under conditions of stress or deficiency rather than as a general tonic. Thus, the evidence is moderate (rated 3), with strong mechanistic support but less robust data from large human trials targeting adrenal support specifically.