Why Low?

Sometimes a patient can still have low serum levels of vitamin D even after months of taking oral supplements. One reason for this, according to a small but striking study at the Cleveland Clinic Foundation, is that some vitamin D resistant people are taking vitamin D supplements on an empty stomach or with a small meal, usually breakfast or lunch.

Twenty five people participated in the study, 17 of them were instructed to take the same supplement they had been taking with their largest meal of the day, usually supper. After 2 to 3 months, taking the same vitamin D supplement with the “largest” meal of the day, researchers found that serum vitamin D levels had increased on average by 56.7%.

This magnitude of increase was seen across a wide range of vitamin D dosages. Clinicians are aware that vitamin D is fat soluble and generally it is recommended that vitamin D be taken with a meal containing fats. However, based on this study, it may be best to take vitamin D with your largest meal of the day, which is likely to contain the most fat.

One of the causes of poor absorption on an empty stomach has to do with stomach HCl (acid) production. As people age and their digestive track becomes compromised, the ability to secrete HCl and digestive enzymes decreases. Also, digesting food takes energy and if someone has been ill for a prolonged period of time their digestive capacity is further reduced.

Better nutrient absorption with food is especially important with the fat soluble vitamins A, D, E, K as well as Coenzyme Q, which must be emulsified by either bile or pancreatic enzymes. Also remember that, since the fat soluble vitamins are just that, fat soluble, you need adequate bile secretion to best absorb them. Therefore, taking these with fatty foods can increase absorption. And, if you are missing a gallbladder, using bile supplements like Ox Bile, may be necessary.

Vitamin D - What are Healthy Levels? 1
In light of the Cleveland Clinic study and considering patient’s compromised digestion and absorption, make sure you take your vitamin D at their largest meal. If you don’t see the clinical results you expect in 30 days, consider adding further digestive support.


If your blood tests for Vitamin D continue to be in the middle or lower range even after supplementing with Vitamin D3, consider:

  1. Take your fat soluble vitamins (A, D, E, K, and Coenzyme Q10) WITH a meal, preferably one containing some good fats to assure proper bile secretion and better absorption.
  2. If you are missing a gallbladder, consider taking 1-2 Ox Bile supplements WITH your meal, along with your vitamins.
  3. Consider taking HCl along with a digestive enzyme along with everything else.
  4. Make sure to look at you VDR genes on your genetic report (call and we can help you) as defects in these genes may suggest a need for higher supplementation value.