deficiency. Avoid extending a high-dose course or combining several vitamin D products without checking the total.
- High-Dose Vitamin C
Being water-soluble does not make vitamin C harmless at every dose. High intakes can increase urinary oxalate, which may contribute to kidney stones in susceptible people.
The evidence is mixed, so it would be misleading to say vitamin C inevitably causes stones. People with kidney disease or a history of oxalate stones should discuss high-dose supplementation with their clinician.
- High-Dose Niacin
Niacin, or vitamin B3, helps the
body function normally. However,
