Vitamin D boosts glutathione substantially, and many people are vitamin D deficient. That is the supplement to take. Taking vitamin D supplements will also boost naturaal killer cell activity, so candida problems while chelating may be decreased. I guess 5,000 IU a day is a good vitamin D dosage to take, however if you rarely get much sunlight, a daily dosage of 10,000 IU may be okay. Some decide to have their vitamin D blood levels monitored. When monitored if the vitamin D levels are very low, sometimes very large doses of vitamin D are prescribed.