Technically speaking, vitamin D is a pre-hormone. It metabolizes into calcitriol, a substance which can unlock numerous binding sites on the human genome. Deficiency is a factor in diabetes, depression, numerous cancers, heart disease, and more. Research indicates that many health conditions could be improved or avoided with higher vitamin D intake.

The Recommended Daily Allowances (RDAs) for vitamin D have been commonly accepted as too low. Recently (Nov 2010), the official vitamin D recommendations increased.

“Specifically, the Institute of Medicine report advocated a doubling of vitamin D intake for infants (to 400 IU), a tripling of vitamin D intake for those between ages 1 and 50 (to 600 IU), a 50 percent hike in those ages 51 to 70 (to 600 IU), and a 33 percent increase for those older than 71 years old (to 800 IU).” The tolerable upper limit was doubled to 4,000IU.

There are not many foods that contain a good deal of vitamin D and most of the vitamin comes instead from the sun. Dietary sources that we recommend include salmon, mackerel, tuna, and mushrooms. The other dietary sources—fortified milk and cereals—are not recommended by Ray & Terry.

Ray & Terry already recommend 1,000-2,000 IU of vitamin D per day for most people. It’s a good idea to test your blood levels to find your optimal dose: just ask your doctor to run a 25(OH)D test. We advise maintaining 50 ng/dl.

We offer a 1,500 IU Vitamin D3 tablet for less than ten cents a dose. Unless you are getting adequate sun exposure, we recommend taking a look at this simple supplement.