Vitamin D - What is It and How Much Do I Need

Knowledge of vitamin D and its importance has helped humans be more healthy since the 17th century. The first scientific description of a vitamin D-deficiency, namely rickets was provided by both Dr. Daniel Whislter and Professor Francis Glisson. Major breakthroughs in understanding of vitamin D actually began in the early 1900s. We now accept that the biologically active form of Vitamin D is a steroid hormone. It is somewhat ironic that through a historical accident vitamin D became classified as a vitamin. During an experiment with dogs, they realized that light equals vitamin D - a natural steroid.

Cod liver oil was shown to be identical to the newly characterized vitamin D. Very early it was known that cod liver oil was an excellent source to help prevent rickets. Rickets is a bone disease overcome because of the science of nutrition and discovery of the families of water-soluble and fat-soluble vitamins.

Technically this "non vitamin" is in a class by itself. Its metabolic product, calcitriol, is a secosteroid hormone that targets more than 2000 genes included in the human body.

Current research has implicated vitamin D deficiency as a major factor in the pathology of at least 17 varieties of cancer. Also it factors in heart disease, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle weakness, muscle wasting, birth defects, periodontal disease and even more.

Thereby we now know that vitamin D's influence on key biological function vital to our health and well-being mandates that vitamin D no longer be ignored by the health care industry. Nor should those of us who strive to have good health care habits, ignore the importance of vitamin D.

It is known that if adults and teens regularly avoid sunlight exposure, they should supplement with at least 5,000 units of vitamin D daily. To obtain this amount from milk, you would need to drink 50 glasses of milk. With a multivitamin, more than 10 tablets would be needed. Neither is advisable. Twenty to thirty minutes of summer sunlight causes the skin to produce approximately 10,000 units of vitamin D. This is far more than the US government's recommendation of 200 units per day.

After reading and understanding just how important vitamin D is to our well-being, how can we insure that our bodies will get enough vitamin D. There are three methods for fulfilling the need of enough vitamin D.

1. Regularly receive midday sun exposure in the late spring, summer and early fall, exposing as much of the skin as possible. Be careful not to get sunburned. It is best not to use sunscreen above 15.

2. Use a sun bed during the colder months. [I would also suggest sitting in sunshine inside a building as much as possible. Sun beds may cause other problems.]

3. Take 5,000 units per day for 2-3 months, then visit your doctor to be vitamin D tested. Adjust your dosage so that blood levels are between 50-80 ng/mL or 125-200 nM/L year round.

Even though many of us spend lots of time out of doors in the summer, it is important to understand that during the winter months the amount of vitamin D in your body may go very low. This factor can be very important when thinking about the great variety of diseases that vitamin D deficiency can have to impact your body and your health.