Vitamin D is often regarded as miraculous because of its capacity to prevent disease and reduce cancer risk and progression, and now scientists have discovered that vitamin D blocks drug-resistant cancer cells — the main cause of failure in chemotherapy treatments. Using cultured tumor cells, researchers from South Dakota State University found that calcitriol and calcipotriol, two active forms of vitamin D, can block a mechanism that enables cancer cells to become drug-resistant, offering hope to patients who are facing chemotherapy treatment for metastatic and leukemic cancers.

Optimal vitamin D levels can slash your risk of cancer by as much as 60% and help prevent at least 16 different types of cancer, including breast, colon, prostate, ovaries, esophagus, lymphatic system and even melanoma. It does this three ways: By destroying mutated cells, which can replicate and cause cancer, by slowing down the production and spread of cancer cells and by helping prevent benign tumors from turning into cancerous ones.

There are about 30,000 genes in your body, and vitamin D affects nearly 3,000 of them, as well as vitamin D receptors located throughout your body.

Vitamin D not only helps with cancer prevention and progression but can also help reduce the risk of other conditions as well, including type 2 diabetes, chronic inflammation, age-related macular degeneration (the leading cause of blindness) and Alzheimer’s disease. It’s infection-fighting abilities aid in the treatment of tuberculosis, pneumonia, colds and flu and it can also improve seizure control in epileptics.

Raising your vitamin D levels not only will help lower your risk of cancers, but is nothing short of amazing in its ability to improve heart function in those with chronic heart failure.

While vitamin D is referred to as a vitamin, it is actually a steroid hormone obtained from sun exposure, food sources and supplementation. Common types of vitamin D are vitamin D2 and D3. Vitamin D3 is preferred because it is 87% more effective than vitamin D2 in raising your levels of this essential vitamin.

The best way to optimize your vitamin D is through regular sun exposure, making sure to measure your levels twice a year. The key word here is “sensible” sun exposure, which means making sure you do not burn so you can maximize your benefits and minimize the risks of skin damage that could lead to skin cancer. It’s overexposure, not avoiding all sun exposure, that is the real problem when it comes to elevating your risk for skin cancer.

If you live in a cold climate with harsh winters and lots of gray skies throughout the year, enjoying some sunshine may be easier said than done. In these cases, oral vitamin D3 (not D2) can be used, although you’ll miss out on other health benefits associated with sun exposure.