LOW VITAMIN D is discussed on this page of parathyroid.com. This is an advanced parathyroid page, and if you have recently been told that you have hyperparathyroidism (parathyroid disease) and/or high calcium in your blood, then PLEASE read our other parathyroid pages first. We will give a short synopsis of Vitamin D in the blood, and low vitamin D levels... with some facts and take away points.  Then, this page will get more complex. If your endocrinologist tells you that your calcium is high because your Vitamin D levels are low... and wants to give you Vitamin D to make your calcium go down... then you MUST print this page and take it to them. THIS IS WRONG. The bottom of this page is complex and written for doctors and advanced patients. The top of this page on Vitamin D is for most patients...  Here we go.

Overview of Vitamin D

Vitamin D is essential to our bodies. We can't make it, so we have to get it in our diet, or get outside and have the sun make it for us (yep, sun light on our skin causes our skin to make Vitamin D.

Vitamin D does ONE THING in our bodies. ONLY ONE THING... it helps our intestine to absorb calcium from the foods we eat. Thus, Vitamin D increases the amount of calcium in our bodies. If our Vitamin D levels are low, then our intestines have a hard time absorbing calcium. This is why milk is fortified with Vitamin D. Did you ever notice that the milk you buy has "Vitamin D Fortified" written on it. We want our kids to drink milk so they get lots of calcium to build their bones strong... but without the Vitamin D, most of the calcium in the milk won't get absorbed. Our intestines MUST have at least a little Vitamin D to absorb calcium. For you older people out there, did you notice that most of the calcium supplements (Citracal, Oscal, Caltrate, etc, etc) will have Vitamin D added to the calcium pills?  This is because our intestines need the Vitamin D molecule to absorb the calcium molecule through the intestinal wall and transport it into our blood.  AGAIN.... Vitamin D does only ONE thing in the human... it helps our intestine to absorb calcium.

Thus, increasing a person's Vitamin D levels will increase the amount of calcium they absorb from their diet. If a person takes more Vitamin D, then the intestines will become more efficient at absorbing the calcium molecules in our diet, and these calcium molecules will be absorbed... your calcium will go UP.

Vitamin D and It's Relationship to Hyperparathyroidism

Hyperparathyroidism is associated with high calcium in the blood. The cause is a parathyroid tumor. This is discussed throughout this website, so we will not go into it here. Basically, a tumor grows from one of your parathyroid glands... this tumor produces parathyroid hormone which takes calcium out of your bones and puts it into your blood. You get osteoporosis and feel bad because of the high calcium in the blood.

The body doesn't want the calcium to be high... So, it will try to get rid of the calcium in the urine... which is why many patients (about 1/3) will have high calcium in the urine (they can get kidney stones from this).

The body also wants to shut down calcium absorption from your intestines. It does this by limiting the amount of Vitamin D in your body. Thus, if your body determines that your calcium is too high... it can decrease the amount of calcium that is absorbed from your intestines by decreasing the amount of Vitamin D available. If your Vitamin D levels are decreased, you can't absorb so much calcium from your diet. This is a protective measure.

Vitamin D in Patients with PRIMARY Hyperparathyroidism

We began measuring Vitamin D levels in patients with hyperparathyroidism in the mid-1990's. For the past several years, we have measured it in most patients, and beginning in 2006 we began measuring Vitamin D in every patient with PRIMARY hyperparathyroidism. Here is what we found:

Well....... what is happening in these patients? What is the difference? Each of these patients had a high calcium levels in their blood and high (or inappropriately normal) PTH levels. Thus, each of them had primary hyperparathyroidism. Well, every one of these patients was operated on by us, and we found (as expected) that they all have the exact same parathyroid tumor! (sorry, we are getting complex now... if we lose you, then go to the basic pages and come back here later). That is, 97% of those with LOW vitamin D levels have a parathyroid adenoma and 3% have hyperplasia. 97% of those with NORMAL Vit D levels have a parathyroid adenoma and 3% have hyperplasia. Thus, there is no difference in these people's necks.......they all have the same parathyroid tumors causing their hyperparathyroidism... The Vitamin D levels have NOTHING to do with their disease.

THEREFORE: IF YOU HAVE HIGH CALCIUM, YOU HAVE A PARATHYROID TUMOR IN YOUR NECK AND YOU NEED AN OPERATION TO REMOVE THE TUMOR. Vitamin D levels have nothing to do with it!  DO NOT AVOID SURGERY BECAUSE YOUR DOCTOR SAYS YOUR VITAMIN D LEVEL IS LOW... AND THE LOW VIT-D IS THE CAUSE OF YOUR PROBLEMS.  THIS IS WRONG!!! This is a myth, and this myth is BUSTED. This is still the case if your calcium goes up and down... high sometimes and back to normal some times..... this is typical for patients with parathyroid tumors. The tumor doesn't regulate the calcium well, and the levels go up and down.

Why are we discussing Vitamin D and hyperparathyroidism?  Because this has become a HUGE problem in late 2006 and 2007! Now that Vitamin D is easy to measure, many doctors (endocrinologists) will measure Vitamin D levels on all patients with high calcium in the blood. They will also measure the PTH levels... they are trying to prove (correctly) that the high calcium in the body is due to a parathyroid tumor.  Here is where they go wrong... and this is getting very complex.... If the Vitamin D level is low, then they think this is the MAIN PROBLEM. They think that the low vitamin D levels cause too little calcium to be absorbed in the intestines. They think that this low amount of calcium is sensed by normal parathyroid glands which causes the normal parathyroid glands to appropriately increase their production... causing a high PTH level. They further believe that this high PTH level will take calcium out of the bones and increase the calcium in the blood. Thus, they think the PTH levels are high because of the low vitamin D levels... thus they think the high PTH levels are high SECONDARY to the low vitamin D levels... thus they will tell you that you have SECONDARY hyperparathyroidism. THIS IS A MYTH. THIS IS NOT CORRECT. Measuring Vit D levels has nothing to do with making the diagnosis of hyperparathyroidism. Low Vit D levels will NEVER cause high calcium levels. It is not possible!

Getting complex even further... If you are still with us... If the low vitamin D was the starting point... if the low Vitamin D was the main problem... and this caused the parathyroid glands to increase their parathyroid hormone production... then I would be an idiot to operate on these people... and if I did, I would find them to all have normal parathyroid glands... they wouldn't have 3 normal parathyroid glands and one parathyroid tumor! If the low Vitamin D caused the parathyroid glands to get big... they would all get big... but that is NOT what happens! Patients with low Vitamin D levels have parathyroid tumors just like people with normal vitamin D levels. Remember, parathyroid adenomas are tumors. The entire tumor mass is made of cells from one parent cell that went crazy and reproduced itself millions of times. Parathyroid adenomas are TUMORS... (did you see our page showing 80 typical photos of these tumors?). Low Vitamin D does not cause TUMORS to grow. It is the other way around. 

To defend the endocrinologists (who mean well, but don't see enough patients with hyperparathyroidism to be "expert" at it... we see 3,500 patients per year with this problem!!), it is possible to have LOW vitamin D levels to cause your PTH to go up. BUT... this will NEVER increase the calcium in the blood, and the PTH will only go up slightly. Sometimes your endocrinologist will try to give you Vitamin D as a trial... to see if your parathyroid problem is due to low Vitamin D.  The theory is that giving you Vitamin D will cure the cause of the high PTH... and all your labs will go back to normal... They call this secondary hyperparathyroidism and they will give you a prescription for high doses of Vitamin D.  HOWEVER, this can be dangerous... if your calcium is above 11.5, the additional Vitamin D can make your calcium go above 12 and we have even seen 2 patients have a stroke because of this. We have even seen an endocrinologist get sued for malpractice because he gave a patient with primary hyperparathyroidism high doses of Vitamin D which caused the patients calcium to go high and cause the patient to have a stroke! This is not a smart move.  If your calcium is high, you should NOT take Vitamin D in large doses. If you do, you will find that it almost always makes your symptoms of hyperparathyroidism worse! Is it going to cause you to have a stroke??? nope.... but it will make you feel bad and it will waste your time and money. If your calcium is high, you have a parathyroid tumor (PRIMARY hyperparathyroidism) regardless of what your Vitamin D level is. 

Remember above when we were discussing Low vitamin D... saying that decreasing the Vit D in your body is the body's way to protect itself from the high calcium?  If this is true, then we should see the low Vitamin D levels in patients with hyperparathyroidism return to NORMAL once the parathyroid tumor is removed.  Well, in January 2007 we began a trial to test this theory scientifically (we had observed it many times, but we decided to test it scientifically so we can publish it in a major medical journal... we publish on parathyroid topics about every other month). Guess what!!!???  95.6% of all patients with LOW vitamin D levels had NORMAL vitamin D levels 1 month after their parathyroid tumor was removed!!  Thus, proving yet another way, the body doesn't like having high calcium which is due to the parathyroid tumor. The body turns off Vit D so we don't absorb as much calcium. When the parathyroid tumor is removed, the body turns the Vitamin D back on and the low vitamin D levels increase back to normal.

The bottom line again:  If your calcium is high, you almost certainly have a parathyroid tumor. If your calcium is high and your Vitamin D is low, you STILL have a parathyroid tumor. If your calcium is high and your Vitamin D is normal, you STILL have a parathyroid tumor.  When you get your parathyroid tumor removed, your Vitamin D level will almost always correct itself within 1 month!

If your endocrinologist says "you have secondary hyperparathyroidism because your Vitamin D level is low", then you MUST print this page and take it to them! This is not correct. You have PRIMARY hyperparathyroidism... and 1/3 of people with primary hyperparathyroidism have a low Vitamin D level... it is expected. Get the tumor removed and get on with your life! Secondary hyperparathyroidism due to low vitamin D is never associated with a high calcium level in your blood. NEVER. If they put you on Vitamin D and then measure your calcium a month later... and your calcium gets better.... then they are fooling you and themselves... it will be bad again one month later, and you will feel bad. Trust me! This will make you feel bad. Get the tumor removed!