1. Feed them vitamin D
The prestigious journal Nature published a study with a stunning discovery: T-cells don’t work very well unless your vitamin D receptors are activated. In other words, T-cells won’t activate without enough vitamin D.
The study also says you can increase your T-cell responsiveness by 750 percent by making sure you have a good amount of vitamin D.
Direct sunshine is best because our bodies make vitamin D from the sun’s rays. If you can’t get some sun every day, it’s best to get at least 3-5,000 IU of D3 daily. You might need as much as 10,000 IU if you’ve been out of the sun for most of this winter already.