The time it takes for the first effects of taking vitamin C to appear can vary from person to person. It depends, among other things, on the degree of any deficiency, your personal health and your lifestyle. As a general guide:
Mild deficiencies:
With a mild deficiency, the first improvements may be noticeable after just a few days to a few weeks. Symptoms such as tiredness or general weakness often improve relatively quickly.
Pronounced deficiencies:
With more severe deficiencies, it can take several weeks to months before clear changes appear. In these cases, the regeneration of skin and hair and the stabilisation of immune functions need more time.
General health support:
If you take vitamin C for long-term health support, you often won't notice any immediate effects. Here, the effects tend to build gradually over time, as a form of preventive health support.