It certainly is the case that they slow with age.
Be very careful supplementing with vitamin c - a piggy with a healthy diet and no signs of scurvy should not be supplemented long term. A course of vit c lasting no more than two weeks is fine to help boost the immune system but longer term supplementing can cause health problems.
The last section of the guide below explains more what longer term vit c supplementing can be harmful
1 Overview of recovery formula foods
- Recommended brands
- Emergency alternatives
2 Probiotics
- Standard brands
- Enhanced probiotics
- Live gut microbiome transfer (poo soup)
3 Vitamin C
- Recommended brand
- Alternatives
- Booster vs. long term supplementation
These chapters have been copied from the complete...