Increased blood calcium and vitamin D

Conventional advice tells us to supplement calcium, 1200 mg per day, to preserve bone health and reduce blood pressure.

Here's a curious observation I've now witnessed a number of times: Some people who supplement this dose of calcium while also supplementing vitamin D sufficient to increase 25-hydroxy vitamin D blood levels to 60-70 ng/ml develop abnormally high levels of blood calcium, hypercalcemia.

This makes sense when you realize that intestinal absorption of calcium doubles or quadruples when vitamin D approaches desirable levels. Full restoration of vitamin D therefore causes a large quantity of calcium to be absorbed, more than you may need. In addition, two studies from New Zealand suggest that 1200-1300 mg calcium with vitamin D per day doubles heart attack risk.

We have 20 years of clinical studies demonstrating the very small benefits of supplementing calcium to stop or slow the deterioration of bone density (osteopenia, osteoporosis). These studies were performed with no vitamin D or with trivial doses, too small to make a difference. I believe those data have been made irrelevant in the modern age in which we "normalize" vitamin D.

Should hypercalcemia develop, it is not good for you. Over long periods of time, abnormal calcium deposition can occur, leading to kidney stones, atherosclerosis, and arthritis.

Until we have clarification on this issue, I have been advising patients to take no more than 600 mg calcium supplements per day. I suspect, however, that the vast majority of us require no calcium at all, provided an overall healthy diet is followed, especially one that does not leach out bone calcium. This means no foods like those made with wheat or containing powerful acids, such as those in carbonated drinks.

Comments (50) -

  • renegadediabetic

    6/21/2010 1:18:12 PM |

    Sometimes I think that the RDAs only apply to the current high refined carb, nutrient depleting diet most americans eat.  

    This is just more proof that the current calcium "requirements" are overstated and probably intended to market dairy products or calcium fortified processed foods.

  • Katie

    6/21/2010 1:42:19 PM |

    I always thought the recommendations for supplementing with calcium were probably wrong.  I've heard that Americans eat more calcium-rich foods and supplement with more calcium than other Western countries, but yet suffer from the highest amount of osteoporosis/osteopenia.  

    This wouldn't surprise me, given the importance of having the right amounts of calcium, Vitamin D, and Vitamin K2.  I've seen other doctors/researchers recommend that Vitamin D always be taken in connection with sufficient intake of Vitamin K2 to help prevent hypercalcemia.  I do not supplement with calcium, but I do supplement with D3 and K2 and have had no problems

  • Anonymous

    6/21/2010 1:45:19 PM |

    Dr. Davis is wheat a bad idea because of the phosphates which demineralize bones ? If so then lentils and peas and beans would be quite high in phosphates too? would the recommendation be to lower their consumption as well?



    6/21/2010 2:56:32 PM |

    Calcium as a supplement is one of the toughest to assimilate in the body- I can't see how an accurate number can be assessed as too much (or too little)

  • scott

    6/21/2010 3:28:53 PM |

    I wonder how much calcium is in Gerolsteiner Water.  Dr. Davis has recommended this in the past, but probably for the magnesium content.

  • Anonymous

    6/21/2010 3:37:16 PM |

    1) It would seem that anyone speaking of vitamin D, is being a little misleading as we should most likely be talking about D-2 or D-3. Or never talking about D-2 and always about D-3 as it is the more bio-active.
    2) Increase K-2 to take care of the D-3 / calcium problem.
    3) Blood tests to keep track of all three of them.

  • miannotta

    6/21/2010 4:51:37 PM |

    Would supplementing with vitamin K2 help alleviate the problem of too much calcium in the blood? It's function is to redirect blood calcium to the bones. Or is the jury still out on this?

  • Anonymous

    6/21/2010 5:20:33 PM |

    This is a point also made in the current posting of "Diabetes Update"

  • Steve

    6/21/2010 6:11:04 PM |

    Apparently alot of people are reporting issues with vitamin d supplementation. You may have hit the nail on the head, Dr Davis. Here is a website that has over 200 comments from people experiencing issues.


  • Jenny

    6/21/2010 6:55:53 PM |

    Since I ran into just this problem (and blogged about it elsewhere) I want to add this:  You don't have to be supplementing with pills to run into this problem.

    If you are eating a classic low carb diet and eating cheese rather than meat for much of your protein your calcium intake can get high pretty fast.

  • Bobber

    6/21/2010 7:19:02 PM |

    Are you familiar with Dr. Cordain's work on Acid/Base balance?

  • Anonymous

    6/21/2010 10:17:14 PM |

    Men don't need more than 626 mg/day calcium, and women with D > 20 ng/ml don't need more than 566 mg/day.

  • Jessica

    6/22/2010 12:43:32 AM |

    We usually recommend that individuals stop taking a calcium supplement once they've reached the target D level (70-90 ng/mL).

    We always draw a serum calcium with a 25(OH) level.

    Detected several cancers in our patients this way (hypercalcemic prior to starting D supplementation).

    Also, I'm about 8 months pregnant with our first child and you think cardiology is behind the times with Vitamin D, try OB! They're living in the dark ages.

    Fortunately my OB is more versed than most and the fact that I take 10,000 IU daily doesn't make him too uncomfortable (obviously not since he didn't offer to check my D level...I had to ask for it).

    I'm also taking 500 mg QD of elemental magnesium (no preeclampsia for me) and (when I remember), 12.5 mg of Iodoral/week (I worry about taking it everyday due to potential for "heavy metal dumping" since I wasn't routinely taking it prior to pregnancy).

    I still take a pre-natal, but I worry more about not taking the other supplements more than i worry about missing a dose of the pre-natal.

    Thanks for all you continue to do in healthcare!

  • cardiology emr

    6/22/2010 1:08:33 AM |

    Thank you so much for the advice I will try having an supplement calcium, to preserve bone health and reduce blood pressure for my own good.


  • Anonymous

    6/22/2010 2:09:39 AM |

    interesting. So does this mean that those areas where the calcium levels in drinking water are high : "hard" or "temporary hard", are areas where high vitamin D could work against residents trying to maintain healthy arteries?


  • Anonymous

    6/22/2010 5:02:05 AM |

    I'm 37 and have been taking 6,000 i.u. of vitamin D per day for the last several months.  I started urinating blood last night and have a CT scan in a few days to see the likely cause of it all - kidney stones.

    My Dad also had them. I think the vitamin D may have contributed in bringing this about.

    Coincidently, I'd started taking Tums (rich in calcium) every now and then for heartburn about a month or two ago.  

    Timely post doc!

  • Anne

    6/22/2010 7:17:17 AM |

    Dear Dr Davis,

    Please can you quote the links to the studies you mention in this blog. I have both osteoporosis and a heart valve defect (bicuspid aortic valve) and calcification is being deposited on the aortic valve. My levels of 25(OH)D range from 60 to 100 ng/ml. I have my bone profile tested every time I have my 25(OH)D tested and so far my serum calcium levels have been in the normal range but your post worries me considerably.


  • moblogs

    6/22/2010 9:03:29 AM |

    I would agree that we probably need no dairy based calcium at all, since it is only necessary at birth through mother's milk.
    Even so, I do like my dairy products in moderation so that's all I take - no additional calcium supplements; and my blood calcium level and bone density has benefited from just D on top.

  • steve

    6/22/2010 3:31:52 PM |

    while current blood levels of D3 may appear to be inadequate, there is no science to demonstrate what the higher levels shuld be.  While a blood level of 60 coming from the sun may be wonderful, there are no studies, let alone ones of any duration, that show that supplementing with large doses of D3 to get to a 60 level do not pose any negative health consequences.  As we have learned with other vitamin supplementation, more is not always better; adverse consequences can arise, and there is not always a way to detect them such as blood calcium levels.  Caution should be the watchword.

  • Steve

    6/22/2010 3:50:56 PM |

    Dr Davis, what is your opinion of the supplement MSM? Does vitamin D have an effect on this also?


  • Anonymous

    6/22/2010 4:24:11 PM |

    Dr. Davis,

    Magnesium competes with calcium absorption, and therefore is crucial to keeping calcium levels at bay.

  • Peter

    6/22/2010 8:11:05 PM |

    I noticed that a study this week found a correlation between very high vitamin D levels and increased risk of pancreatic cancer.

  • nightrite

    6/22/2010 9:53:05 PM |

    I too had trouble with kidney stones untill I began supplementing with magnesium.  I take 600mg of various forms of mag and no longer have any problems with kidney stones.  I also take 6000 units of D3 and 180 of K2.  I have not had my serum calcium checked but don't eat too much dairy.

  • Anonymous

    6/22/2010 10:19:44 PM |

    What about high phytic acid foods like the raw almonds and cocoa advocated here?  Don't those contain as much or more calcium binding phytic acid as wheat?  I eat very low carb and no dairy products whatsoever.  My indulgences have been raw hazelnuts and cocoa -- now I'm wondering if this has been damaging in some way.  My understanding is that serum calcium represents only 1% of body's calcium and that an ionized calcium test is more accurate.  My doc drew blood today to re-check my vitamin d status but would not check mineral status.

  • Anonymous

    6/22/2010 10:26:31 PM |

    Different take on the calcium for me.  When I develop a faint, "fluttery", tachycardia (up to about 142 for a 63-year-old, and I feel absolutely horrible) I take about 500 mg of calcium citrate with about 1000 mg of vitamin C (for absorption of the calcium) and the heart beat gets stronger and the rate comes down.  Sometimes I have to repeat.  I found only one internet reference to this phenomenon below:

    I do not have access to health care as I am one of the working poor.  Perhaps you can comment, Dr. Davis.  Thanks, Catherine

  • Dr. William Davis

    6/22/2010 10:30:07 PM |

    Hi, Jessica--

    I think that you and your group are managing the calcium/vit D issue the right way.

    Unfortunately, some people are wrongly interpreting this to mean that vitamin D causes hypercalcemia. It simply means that calcium is unnecessary when D is restored.

  • Dr. William Davis

    6/22/2010 10:31:32 PM |


    Thanks for the clarification.

    Thankfully, your situation is the exception. Most people maintain normal calcium levels even while consuming dairy and other calcium-rich foods.

    Several responders here make the point about magnesium, which I agree with. Have you addressed magnesium? Magnesium deficiency is exceptionally common, since it has been taken out of most drinking water.

  • Anonymous

    6/23/2010 2:29:29 AM |

    I noticed that a study this week found a correlation between very high vitamin D levels and increased risk of pancreatic cancer.

    Cited are NOT very high levels! The claim is higher rates of pancreatic cancers with >100 nmol/ml - which translates into 40 ng/ml, a level considerably lower than the one recommended here by Dr. Davis (~60-70 ng/ml if I remember correctly). Another claim is NO difference in rates of several other cancers across a large range of 25(OH)D concentrations.

  • LeonRover

    6/23/2010 9:11:25 AM |

    Peter's comment above led me to read the newswire report referred to.

    This study was trying to establish any epidemiological association of increased levels of Vit D with reduced incidences of various cancers. No such associations were observed. Rather in the case of pancreatic cancer only, it was observed that when the  level of Vitamin D was GREATER than 100 nmol per litre, there was higher incidence of this disease. Another way of looking at this observation is that at levels below 100 nmol per litre there was no association of pancreatic cancer with levels of Vit D LOWER than 100 nmol per litre.

    As far as cancers are concerned there is no point in considering Vit D status as long as it below 100 nmol per litre.

  • Mike

    6/23/2010 10:07:09 PM |

    This is timely. I just had blood work done recently and my Dr.'s staff ordered the wrong test. Instead of measuring D3, they measured D2 calcitriol. I don't know what to make of the result: 120.8 pg/mL on a scale of 10.0-75.0. It's extremely high.  The last time I had my vitamin D3 tested, it was 59.2 ng/mL on a scale of 32-100.
    FWIW, I follow a low carbohydrate Paleo diet and consume very little dairy. I do take a multivitamin 3-5 days per week, but it only provides 300 mg of calcium (along with 210 mg of magnesium). I also take 500 mg of magnesium citrate every evening.
    I'd sure like to know what to make of this.

  • TedHutchinson

    6/24/2010 7:54:39 AM |

    @ LeonRover
    The information on pancreatic cancer & vitamin D status comes from Finland

    The further from the equator the greater the swing from high to low status. To have a good shower requires tight regulation of both hot and cold water supplies and a reserve store of both hot and cold supply so neither ever runs out.

    Vieth explains in this paper.
    How to Optimize Vitamin D Supplementation to Prevent Cancer

    In the same way fluctuating concentrations of 25(OH)D may also be a problem, Regions at high latitude or with low environmental
    ultraviolet light can be associated with the greater risks reported for prostate and pancreatic cancers. At temperate latitudes, higher summertime 25(OH)D levels are followed by sharper declines in 25(OH)D, causing inappropriately low 1-hydroxylase and high 24-hydroxylase, resulting in tissue 1,25(OH)2D below its ideal set-point.

    The answer is to keep levels BOTH HIGH and STABLE.
    Humans only build a stored reserve of D3 in tissue above 40ng/ml = 100nmol/l. Only around 60ng/ml are there sufficient D3 reserves for lactating mothers to pass to babies in breast milk. At latitude 32 it takes modern women 6400iu/daily/D3 to provide naturally replete vitamin D breast milk.

  • Mike

    6/24/2010 8:30:44 PM |

    Thanks Ted. That clarifies the role of calcitriol, but I am still wondering why my level measured so high, if even transiently.

  • Anonymous

    6/24/2010 8:37:38 PM |

    I'm anonymous from above who talked about kidney stones and blood in my urine.

    I had the CT scan done yesterday. I have stones, one of them a whopping 1.4 cm.  

    Be careful people.

  • Catherine

    6/25/2010 10:07:09 PM |

    (I am a different Catherine than the one above with tachycardia)

    For years because I had osteopenia, I was advised to take loads of calcium.  Later they told us to add vitamin D with it.  I am now FULL of calcium deposits all over my body.

    A year ago, Dr. Davis advised me to try magnesium for a bad arrhythmia problem, and it not only quickly cured my arrhythmia, insomnia, and RLS, but I have much less grinding sounds and arthritis pain. I was the poster girl for magnesium deficiency and no one except Dr. Davis even mentioned trying it.

    I think along with K2, magnesium is of upmost importance to balance the D and calcium. I only take 500 mg a day now since I don't consume dairy, but after this article, I may totally stop supplementing any calcium and let the K2 and magnesium perhaps reduce some of the deposits..

  • Anonymous

    6/27/2010 12:24:40 AM |

    @Mike -- I have the same issue/question.  My 25 OH was 62 but the 125 test was sky high.  My serium calcium was normal.  I wonder if Holick's new book gives detailed info on how to interpret lab tests.  His first book just said that the correcxt test is the 25 OH but didn't explain if there is any danger is a sky high 125.

  • Crystal

    7/4/2010 6:44:07 AM |

    This is an awesome post. Great post. Thanks for sharing this. Looking forward to read more from you.
    Green Tea

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  • Anonymous

    12/27/2010 7:27:18 PM |

    Dr. Davis,
    Since increasing my Vitamin D, Magesium and Melatonin I suddenly have very brittle, splitting fingernails.  Any idea which if any of these caused this?  Any suggestions?

    Love your blog!!!!!

  • Jack

    3/4/2011 4:13:40 PM |

    Chances are the calcium supplement you are taking now is a rock source of calcium. The label will say "calcium carbonate", which is nothing more than limestone. AlgaeCal Plus contains an organic, plant-sourced calcium form derived from a unique South American marine algae called Algas Calcareasâ„¢.

  • Emr reviews

    4/2/2011 12:01:36 AM |

    think one of the greatest hurdles is overcoming misconceptions in the minds of regulators, doctors and patients alike. I just returned from a trip to Germany and colleagues there are amused about America's 3rd World-like medical records situation

  • Anonymous

    4/2/2011 8:43:46 PM |

    I have celiac disease and osteopenia in my spine and no bone loss in my hips. I have a strong family history of osteoporosis as well.

    Because my calcium intake is less than or equal to 500 mg I take:

    600 mg calcium citrate at two seperate meals

    1200 IU's D3

    500 mg magnesium citrate

    I track using fitday. I'm grain, legume, dairy, sugar and processed food free and follow a paleo type dietary plan.

    Is this okay?

  • Anonymous

    4/2/2011 11:04:23 PM |

    I meant:

    600 mg calcium citrate in total but dosage is split between two seperate meals.

  • Dave

    5/2/2011 11:25:59 PM |

    I've seen research that shows the body produces more MGP and other calcium handling proteins with higher doses of Vitamin D.  You would expect this effect as a evolutionary collaboration with Vitamin D activity.  Higher doses of Vitamin K2 are needed to carboxylate these proteins and make them active.  These proteins are active in various places in the body like the arteries and the kidneys.  I have a theory that taking Vitamin K2 helps prevent kidney stones and maybe gallbladder stones of the calcium type.

    Uncarboxylated MGP is actually worse than the fully carboxylated MGP.  Guinea pigs are given cholesterol and high levels of Vitamin D in research to give them artery disease by exceeding their Vitamin K2 levels thus creating low carboxylation levels.

    More Vitamin K2 may well be good for those kidney stones.

  • Dave

    5/3/2011 12:14:43 AM |

    There is recent and startling Dutch research to the point that Vitamin K2 is specifically used to carboxylate calcium handling proteins that remove calcium from the arteries and promote heart health.  If you are taking extra Vitamin D, the body also generates more of these calcium handling proteins so the need for Vitamin K2 also increases.

    I had good experience over six months with taking Vitamin K2 and found my running speed increased by 8% and the itching or other mild, variable sensations in my chest have decreased 98%.  I suspect this is connected to reduction of calcification.  I noticed a reduction in my symptoms after six weeks.

    My Vitamin K2 has:
      1300 mcg Vitamin K2, Mk-4
       100 mcg Vitamin K2, MK-7
      1000 mcg Vitamin K (the ordinary stuff)

  • Reikime

    9/22/2011 2:02:34 AM |

    Reading all these posts I used to think of vitamin D and magnesium and K2 the same a most posters. Intuitively never took calcium, was up to 6000 mg of D3/ day to achieve a level of 43- up from 26.

    That said, my serum calcium has trended upward to 10.3. I am now having a few blood tests to check  for hyperparathyroidism!  The foremost parathyroid doc in the USA is Dr. James Norman from Tampa, and his website is very informative and puts a different spin on what I thought I knew of these matters. Parathyroids is ALL he and his 2 colleagues do all day every day. Please give this a look to be fully informed on the matter of Vitamin D supplementation.
    I have no connection, but if I find out I have an adenoma on one of my parathyroids, this is where I will have it removed!
    Jeanne ( RN,BSN)

  • Reikime

    9/22/2011 2:05:44 AM |

    Oops,  meant to add I have also supplemented with 400-800mg of magnesium and 1 Life Extension K2 in addition to the Vitamin D for several years.