Vitamin D-3 in my mind is one of the top 3 supplements you need to take on a daily basis. The amount is up to you (be careful of diminishing returns), but along with a the KetoGenics Multi-Vitamin and Fish Oil these are a necessity. Working indoors and living in a part of the world the sun forgets about Vitamin D supplementation is essential. Since taking these I've been much less sick, seen my doctor less and feel great! Capsules of sunshine right to my door!!