This Vitamin D3 supplement is produced by RxVitamins. It contains extra virgin olive oil and Vitamin D3 obtained from the lanolin in sheep's wool.
Just like humans, several mammals do make Vitamin D from the sun's rays and it can be stored in the subcutaneous fat layers. There are no other ingredients other than extra virgin olive oil and the Vitamin D3 obtained from the sheep's lanolin.
This product has tested effective by yours truly, John Slattery. I have taken this supplement, and this supplement only, between testing in October and testing my Vitamin D levels again in March. Throughout the winter I only obtained my Vitamin D from food (minimal amount) and this supplement and my levels rose.
With adequate sun exposure and sufficient synthesis of Vitamin D, one can relay on the sun when the sun is high enough to allow for its UVB rays to penetrate the atmosphere. This timeframe generally falls between March and October in much of North America.
We otherwise require supplementation from food or supplements such as this one.
Each individual's synthesis and utilization of Vitamin D in its active form may vary.
It is always best to have your levels tested to ascertain how much you may need.
This product is gluten/dairy/yeast/soy/sugar free.