Without Vitamin D, specifically Vitamin D3, your immune system will not be healthy. In addition to maintaining healthy calcium levels, Vitamin D regulates hormone secretion and keeps the immune system robust. Vitamin D regulates the function of a variety of tissues and almost all tissues in your body have specific Vitamin D receptors. Vitamin D lowers blood pressure in individuals with hypertension, helps to reduce flu symptoms, heals diseases and prevents certain cancers. Vitamin D deficiency is associated with heart disease, insulin resistance, depression, Seasonal Affective Disorder, acne and migraines.Researchers at Georgetown University Medical Center in Washington, D.C. discovered a connection between high vitamin D intake and reduced risk of breast cancer. These findings, presented at the American Association for Cancer Research, revealed that increased doses of Vitamin D were linked to a 75 percent reduction in overall cancer growth and 50 percent reduction in tumor cases among those already having the disease. Of interest was the capacity of vitamin supplementation to help control the development and growth of breast cancer especially estrogen-sensitive breast cancer.Vitamin D is also extremely beneficial to children. In a study published in the Cambridge Journals, it was discovered that vitamin D deficiency predisposes children to respiratory diseases. Research conducted in Japan revealed that asthma attacks in school children were significantly lowered in those subjects taking a daily vitamin D supplement.Check your Vitamin D levels periodically and supplement accordingly. The best form of Vitamin D is natural sunlight exposure for thirty minutes every other day without sunscreen. Using SPF 8 reduces the production of Vitamin D by 95%. Avoid the sun when UVA radiation levels are at their highest. Other convenient ways to supplement is either orally or with weekly Vitamin D injections. Make sure your Vitamin D3 is from a reputable source and that you are taking a high enough dosage for best results.Interested in supplementing with Vitamin D3? Check out the benefits of having Vitamin D3 injections.