VITAMIN D is discussed on this page of parathyroid.com. If you have been told that you
have low vitamin D then this page is for you. There are two reasons for
having low vitamin D. One reason for low vitamin D is not serious and
simply means you need to take some vitamin D pills. The second reason for
a low vitamin D is much more serious (and less common) and may indicate
that you have primary hyperparathyroidism and need an operation to remove
a small parathyroid tumor. These folks should not be taking vitamin D
until after the parathyroid operation. If you have low vitamin D, you must
understand which of these two groups you are in.
We will give a
short synopsis of Vitamin D in the blood, and what Vitamin D does for our
some facts and take away points. If your doctor put you on high
doses of vitamin D, then you must know why your vitamin D is low. If your
the words "secondary hyperparathyroidism" to you and put you on
high doses of vitamin D because your calcium is not normal then you need
to read this page and watch the video. We will explain this graph
so you are smart! 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).
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) 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.
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.
Let's Graph the Two Causes of Low Vitamin D
The following graph illustrates that there are two causes of Low
Vitamin D: The first is that it is just low because you aren't
getting enough of it in your diet and/or you are not going outside enough
(vitamin D is made in our skin when exposed to the sun) (the yellow blob). The second
reason for a low vitamin D is that you have primary hyperparathyroidism
due to a small tumor in your neck and the
body shuts down the vitamin D (the blue blob). In the graph below we have shown Vitamin D
Levels on the vertical (Y) axis, and Blood Calcium Levels on the
horizontal (X) axis. The green box represents most people who have normal
vitamin D levels (between 30 and 65) and normal calcium levels (in adults
over 35) (between 9.0 and 10.1). The blue blob represents the vitamin D
levels in 18,000 of our patients who we operated on for primary
hyperparathyroidism. You can see that most people with a parathyroid tumor
(primary hyperparathyroidism) have low vitamin D. In fact, the smaller
purple circle shows where 80% of all patients with primary
hyperparathyroidism are on this graph... they have calcium levels between
10.2 and 11.4, and Vitamin D levels between 8.5 and 33.1. Thus, almost
everybody with primary hyperparathyroidism (due to a parathyroid tumor in
your neck) will have low vitamin D. You can tell the difference because
the calcium level is 10.2 or higher.
Let's keep looking at this graph... If you really have low
vitamin D (and not a parathyroid tumor), for which your doctor may want to give you vitamin D pills,
then you should have a normal or LOW blood calcium. This is represented by
the yellow blob--people who have low vitamin D can develop a low blood
calcium level, but usually we have so much reserves (our bones) that almost
all people with a low vitamin D-25 level due to the fact that they don't
get enough Vitamin D in their diet or they don't go out in the sun enough will have normal blood calcium.
This very important graph is included in the CalciumPro
Parathyroid Diagnosis and Risk-Assessment app. Download the Pro-version of
this app ($5.99) so you can graph your personal vitamin D and
calcium levels. The app is very accurate and will tell you if you have a
parathyroid problem or a vitamin D problem. If it doesn't, we will send
your money back. Guaranteed!
Here is the most important fact on this page: since
vitamin D is required for humans to absorb calcium in their intestines, a
low vitamin D cannot ever be the cause of high blood calcium. This
fact is not debatable. Thus, if you have a low vitamin D and your
calcium is above 10.0, then the high calcium in your blood must have come
from somewhere else other than your diet (it came from your bones). Thus,
if you have a low vitamin D, and a calcium level above 10.1, then you are
almost guaranteed to have primary hyperparathyroidism and need surgery to
remove the parathyroid tumor. A low vitamin D cannot ever be the cause of
high blood calcium. Keep reading, because most doctors get confused
between the yellow and the blue blobs.
My Doctor Said I May Have Secondary
My Doctor Gave me LOTS of Vitamin D for my Low Vitamin D Level.
The most common mistake we see from family doctors and
endocrinologists regarding the diagnosis of primary hyperparathyroidism is
that the low vitamin D confuses them and they think the patient has
SECONDARY hyperparathyroidism. In other words, they think the low vitamin
D was the CAUSE of the high blood calcium because the low vitamin D caused
the parathyroid glands to become over-active. They then think that they
can fix the high calcium by giving you high doses of vitamin D. We're here to tell you
that there is no such thing as secondary hyperparathyroidism caused by low
vitamin D that results in calcium levels above 10.1. No Such
These doctors don't understand the graph above, and don't understand that
almost all patients (84%) with primary hyperparathyroidism have a low
vitamin D (average was 21.4 ng/ml in our last 18,000 patients--right in
of the blue blob). So, these doctors will say: "your vitamin D
is low, and your calcium is a little high, I think you may have secondary
hyperparathyroidism due to the low vitamin D, so here is a prescription
for 10,000 (or 50,000) units of vitamin D. Take this high dose of
vitamin D and come back in 3 months and we will check your calcium and
vitamin D levels again". Trust me folks, those exact words will
be said--we hear it dozens of times per day--and it is wrong every time.
Since vitamin D is required to absorb calcium in our diet (this is the
primary function of vitamin D), then a low vitamin D will cause you to
calcium, not more.
If you are over 35 years of age, and your blood calcium is high (over 10.1) you are almost
certain to have primary hyperparathyroidism--a disease caused by a tumor.
If your blood calcium is high and your vitamin D level is low, then you
are almost guaranteed to have a parathyroid tumor (primary
hyperparathyroidism). Keep reading... you are learning a lot here, and
will know more than your doctor in about 5 more minutes.
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 should print this page and take it
to them. This is wrong. You should also download the CalciumPro
app on your iPad, iPhone, or Android phone/tablet. The CalciumPro app
will graph your data so you can show it to your doctor. If you have read
this far down on this page, then you need this app--it will save you from
getting lots of silly tests and wasting your time and money. If it
doesn't, we'll send your $5.99 back to you.
Vitamin D and It's Relationship to 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.
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).
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 2003 we began measuring
Vitamin D in every patient with PRIMARY hyperparathyroidism. Here is what
we found in our recently published article on 10,000 patients with primary
of all patients with primary hyperparathyroidism will have LOW Vitamin D-25
Levels! This is 8,397 patients out of 10,000 in our study. 3812 patients (38%) had
levels below 20 ng/ml with an average
Vitamin D level of 14.6.
average Vitamin D level in patients with a parathyroid tumor removed at
surgery was 21.4
of all patients with primary hyperparathyroidism will have NORMAL
Vitamin D-25 Levels (above 30). Their
average Vitamin D level was 35.3 ng/ml.
of all patients with primary hyperparathyroidism will have HIGH Vitamin
D-25 Levels (we've only seen it once or twice when examining Vitamin-D levels in
over 18000 patients with parathyroid tumors).
the calcium level increases, the level of Vitamin D-25 decreases. The
following graph shows this nicely. When we look at 10,000 patients with a
parathyroid tumor (we know it because we removed the tumor and gave the
patient a picture of it), we see that those with higher calcium levels tend to
have lower Vitamin D levels. As you will read below, this is because the
body is trying to protect itself from the high calcium, and it is
converting one form of Vitamin D (Vit-D-25) into another form
(Vit-D-1-25). This serves to decrease the amount of calcium absorbed
from our diet, to keep the calcium from getting even higher. Read that
again... the body is protecting itself from the high calcium. It does
this by decreasing the amount of Vitamin D in our body so we don't
absorb as much calcium in our diet. As you can see from the graph below,
the higher a patient's calcium goes, the lower the Vitamin D goes.
Figure 1: Vitamin D-25 levels in
with primary hyperparathyroidism due to a parathyroid tumor. This
graph shows the average Vit-D-25 level for all patients.
The line is an average, so there are about half of the patients
who have levels above the line, and about half of them have levels
below the line. As you can see, the line goes down as the calcium
levels increase. Said more scientifically, Vitamin-D25 levels decreased linearly as
calcium levels increased such that 79% of those with calcium levels above 12 mg/dl
had Vitamin-D25 less than 20 (p<0.0001, R=0.91).
Most patients with a parathyroid tumor will have low
Vitamin D-25 levels. Those patients with more severe primary
hyperparathyroidism (those with larger tumors and those who have had the
tumor a longer time) will have higher blood calcium levels, which are
associated with lower Vitamin D-25 levels. The lower your Vitamin D-25,
the longer you have had hyperparathyroidism and a parathyroid tumor in
have graphed this information using a different graph so you can see it clearly. This
shows that nearly 40% of all patients with PRIMARY hyperparathyroidism
have Vitamin D-25 levels that are below 20 ng/ml. 60% have vitamin D
levels above 20, but that includes 29% who have levels between
20 and 30, which is considered "deficient". Nobody
with a parathyroid tumor has high Vitamin D-25 levels. Thus, their body is trying to protect them
from the high calcium, decreasing the amount of Vitamin D levels
so they don't absorb so much calcium.
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, 98% of
those with LOW vitamin D levels have a parathyroid adenoma and 2% have
hyperplasia. 98% of those with NORMAL Vit D-25 levels have a parathyroid
adenoma and 2% 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. It is the parathyroid tumor that is causing the body to decrease
the amount of Vitamin D-25. Not visa versa.
This graph shows that 98% of people with primary
hyperparathyroidism have a parathyroid adenoma (tumor) and 2% have
hyperplasia... REGARDLESS of what their Vitamin D level is. Thus,
if your calcium is high, you have a parathyroid tumor and it
doesn't matter what your Vitamin D level is. The vitamin D is not
causing the parathyroid problem... The low vitamin D is GOOD... it
is protecting you from even higher calcium levels.
If you have high blood calcium and low vitamin D, you must have a
parathyroid tumor in the neck and you need an operation to remove the
tumor. It is a tumor and it will not go away.
Vitamin D levels have nothing to do
with it--except to prove that the source of the high blood calcium is your
bones, not your diet. The low vitamin-D levels is the body's way of preventing the
intestines from absorbing more calcium. The body is protecting
itself! Do not avoid parathyroid surgery because your doctor
says your vitamin D level is low, and that the low vitamin D is the cause
of your problems. This is silly and there is no way our body's can do
this. If your doctor says that, then he/she doesn't understand the
difference between the yellow blob and the blue blob in the graph above.
This is a myth, and this myth is
The low Vitamin D did NOT cause the high PTH and high calcium... in truth,
the parathyroid tumor is making PTH which is taking calcium out of the
bones and putting it into the blood. Furthermore, it is very
typical for patients with parathyroid tumors to have calcium levels that
go 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 since 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 vitamin 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.
This video shows a lecture of Dr Norman at the 2010
Annual Meeting of the American College of Endocrinology (discussing the
"secondary hyperparathyroidism" myth).
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 we would be idiots to operate on
these people... and if we did, we 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 four 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.
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, that is extremely rare, 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 Vitamin 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!? 85% of all patients with LOW
vitamin D levels had NORMAL vitamin D levels 3 months 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 a few months.
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 87% of people with primary
hyperparathyroidism have a low Vitamin D level (below 30 ng/ml). This 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!
Dr Norman is trying to teach!
In June 2009 Dr Norman gave a lecture to the Endocrine
Society's Annual Meeting in San Francisco, CA on Vitamin D in
parathyroid disease. Here is an abstract of this talk; the journal
article was published in 2009. Print this and take it to
your doctor who put you on Vitamin-D. Most endocrinologists know
this already, but many do not:
Vitamin D -25 is suppressed and Vitamin
D-1-25 is increased in patients
with primary hyperparathyroidism in linear fashion as calcium
levels increase, returning to normal within weeks of tumor
removal. A protective mechanism is in play.
Vitamin D-25 is converted to Vitamin D-1-25 in patients
with primary HPT in a linear fashion as calcium levels increase.
Thus the vast majority of patients with primary HPT will have low
Vit D-25 that normalizes by itself in most patients within several
D-25 is often measured in patients with apparent primary HPT to
rule out a possible secondary cause. This study was undertaken to
examine if a relationship exists between Vit-D levels and
parathyroid pathology in patients with elevated calcium levels.
A prospective, single institution study measured
preoperative Vitamin D (25OH and 1-25OH) in 1,587 patients
undergoing surgery for sporadic primary
hyperparathyroidism (PHPT) over a 1-year period.
All patients underwent curative parathyroidectomy with
pathology noted. Patients were put on nominal doses of Vit-D
postop contained within supplemental calcium tablets (Citracal+D;
250 IU cholecalciferol daily) for two months; none took additional
Vit-D. Blood levels were measured at 1 and 2 months post-op.
patients had primary HPT with high serum calcium and PTH preop that normalized at
all postop measures indicating cure. The average preop Vit-D25 was
25.8+10 ng/ml (range 4-65). 1039 patients (67%) had Vit-D25
levels below 30 ng/ml preop, while 594 patients (38%) had levels
below 20 ng/ml preop (mean 14.6, range 4-19), No patient had high
Vit-D25 preop. Vit-D25 levels decreased linearly as calcium levels
increased such that 71% of those with levels above 12 mg/dl had
Vit-D25 <20 (p<0.01, R=0.91).The levels of Vit-D1-25 were
low in 0%, normal in 58.5%, and high in 41.5% (mean 56.2 +
findings at surgery were identical (p=0.98) for those with low vs.
normal Vit-D25 (single adenoma=92%, double adenoma=6%, 4-gland
hyperplasia=3%). 82% of patients with low preop Vit-D25 had
increased levels at 1 month postop (mean 41.4+12, range
17-63, p<0.005), increasing to 91% at 2 months. All patients
with normal Vit-D25 preop remained normal postop. 68%
Vit-D1-25 into the normal range (p<0.001) within 1 month of
Vit-D25 levels decrease in a linear fashion as calcium
levels rise in patients with primary HPT. Overall, 38% will have
Vit-D25 levels less than 20 ng/ml, increasing to 71% of those with
calcium levels above 12mg/dl. Vit-D1-25 shows the opposite pattern
suggesting a protective mechanism. The pathology found at surgery
is identical in PHPT patients with low versus normal Vit-D25
indicating no causal relationship. Low Vit-D25 should not be
interpreted as signaling secondary HPT in patients with elevated
calcium levels. The vast majority of patients will normalize their
low Vit-D25 and high Vit-D1-25 levels within 2 months of tumor