Being skeptical in supplements sold online for a cheaper price is a way to save yourself from scam and dangers of unknown chemicals. Better to invest and look at the ingredients properly than to risk your health.
Vitamin D does something to your immune system. It actually modulates, fights diseases, and boosts weight loss. Aside from Vitamin D, you also need to consider other nutrients you need to take if you want to boost your immune system.
Well, N2 Slin does help your body to utilize the calories you have in your body. Basically, these calories are used to fuel muscle growth and stop the build up of adipose tissues or fats.