It is also important for blood clotting and optimal function of the thyroid gland. Take vitamin D with calcium. Avoid taking mineral oil or products containing mineral oil.
Mineral oil can interfere with vitamin D absorption.
Avoid overuse of antacids. They will interfere with absorption. If you have perpetual digestive problems, consult with your doctor. Check your medications. Some can interfere with absorption of vitamin D, such as cortisone and other steroids.