Proper preparation of vitamin D is important to ensure adequate nutrition and usefulness to treating or preventing seasonal affective disorder (SAD), fall prevention, multiple sclerosis, chemoprevention of cancer, metabolic syndrome, and accelerated fracture healing. The preparations of vitamin D, preferably an edible oil, ranges from 200 IU to 20,000 IU with 2,000 IU being the most preferred. Vitamin D works as an anti-depressant, a high-renin hypertension, and an anti-hypertensive for renovascular hypertension. According to the National Institutes of Health Dietary Supplement Fact Sheet for Vitamin D, it has been found that vitamin D main purpose is to maintain normal blood levels of calcium and phosphorus. This vitamin, combined with other vitamins and minerals, can promote bone materialization, may help maintain a healthy immune system, and regulate cell growth. As for supplementation, the Institute of Medicine of the National Academy of Sciences recommends an Adequate Intake (AI)—the amount of vitamin D needed to maintain bone health and normal calcium levels. In addition, The Institute of Medicine has reported that too much vitamin D intake can lead to nausea, vomiting, poor appetite, weakness, and more.