Yes supplements can be a double-edged sword and must be in balance, etc., etc., etc., I am very careful how my supplements are balanced, but there may be one exception to this rule, vitamin D3. It mostly comes from sunlight and doesn’t need to be counterbalanced with other nutrients.
Here is an excellent video about
vitamin D and cancer by some grassroots academics from the University of California. They are not paid to spread this information. This is 30 minutes long but to get to the heart of the matter skip the first 8 minutes and 25 seconds and watch up to the 11 minute mark. A total of 2 and ½ minutes. Fascinating.
www.youtube.com/watch?v=TQ-qekFoi-o