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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Odd case of hypercalcemia following vitamin D supplementation

In January of 2012, Dr. Jacqueline Marcus and colleagues from the University of California at San Francisco reported on a 58-year-old woman who developed high blood calcium on a physiological dose of vitamin D, combined with an excessive dose of calcium.

Marcus JF et al. Severe hypercalcemia following vitamin D supplementation in a patient with multiple sclerosis. Archive of Neurology Vol. 69 No. 1, January 2012.

The patient suffered from multiple sclerosis (MS) and was trying to reduce the number of MS attacks by taking vitamin D. She became dehydrated, lethargic, had abdominal pain, impaired balance, weakness, slurred speech, tremors, and two hours of difficulty speaking and so came to the hospital. She had high blood calcium (14.6) and low magnesium (1.3). She reported that she was taking a 5,000 IU capsule of vitamin D daily, together with a combination vitamin D/calcium tablet. The doctors report that her total vitamin D intake was 5,500 IU/day and her total calcium intake was 2,200 mg/day. She responded well to IV fluids and within several hours was better and claimed to have forgotten all about the episode.

Her 25(OH)D level was 103 ng/ml (method of measurement not reported), her parathyroid hormone was low (indicating no evidence of primary hyperparathyroidism at the time of the episode) and (six weeks after the episode) her 1,25 di-hydroxy-vitamin D was normal, indicating that (six weeks after the episode) she was not suffering from any type of immune malfunction that caused a moderate dose of vitamin D to elevate blood calcium levels.

One of the takeaway messages is that calcium supplementation needs to be rethought. Scientists conducted the research about calcium requirements of 1200 mg/day on mostly vitamin D deficient patients. Vitamin D increases active calcium absorption, so people with adequate vitamin D levels do not need to take doses of calcium required for passive absorption. I suspect few vitamin D sufficient people need more than 500 mg/day of supplementary calcium.

However, I would be happier if Dr. Marcus had taken a few steps to be certain the patient was not exceeding the recommended 5,000 IU/day. MS is a disease that makes people look for help anywhere, including 50,000 IU capsules. How much did her relatives say she was taking? Did someone sit down with this woman who was claiming amnesia and carefully interview her for evidence she was taking extra vitamin D? Her 25(OH)D level of 103 ng/ml is not inconsistent with 50,000 IU/day but is generally inconsistent with what we know of 5,000 IU/day. In fact, this is the first adult that I am aware of who achieved a blood level of 103 ng/ml on 5,000 IU/day.

Furthermore, what was the vitamin D content of the capsules she was taking? It is easy to analyze the vitamin D content of capsules to rule out a manufacturing error, which is not uncommon. Do you remember Mr. Gary Null?

  About: John Cannell, MD

Dr. John Cannell is founder of the Vitamin D Council. He has written many peer-reviewed papers on vitamin D and speaks frequently across the United States on the subject. Dr. Cannell holds an M.D. and has served the medical field as a general practitioner, emergency physician, and psychiatrist.

6 Responses to Odd case of hypercalcemia following vitamin D supplementation

  1. John says:

    Hi, Dr Cannell. This article brings up the question of milk consumption. You have said before that Vitamin D sufficient people get all the calcium they need from their diets. Since hardly anyone drinks milk any more, do you consider drinking a quart of more of milk a day to be part of a normal diet or is it a supplment? Should milk consumption be avoided in the Vitamin D sufficient? How about people who are MORE than Vitamin D sufficient, like life guards or southern construction workers? Is anyone ever at risk of getting too much calcium from sources other than pills?



    • Brant Cebulla says:

      Good issues you have brought up John. I think drinking milk is still fairly common. I think about half of Americans consume 1-2 glasses per day, not to mention cheese consumption.

      RDA for calcium is 1000-1300mg. Ancestral humans (hunter-gatherers) had about 1000-1500mg daily intake. The big difference here, however, is sources. 21st diet gets calcium from dairy, supplements and fortified grains. Ancestral humans got their calcium from collards, spinach, kale, fish, nuts and seeds.

      This is an area that needs a lot more study, I think that is about as much as you can say. For me personally, I believe in maintaining ancestral vitamin D levels, so I also believe in ancestral calcium intake. I doubt people are getting excessive calcium via their diets — I know of no one who drinks milk, consumes cheese and makes sure to get their hearty leafy greens. Dairy consumption is quietly controversial, too, in regards to its efficacy in maintaining strong bones.

      Would love to hear other thoughts on this…

  2. First, apparently there was not a 25-hydroxyvitamin D level prior to taking the 5000 Units of Vitamin D. Even though she has MS, it’s possible she had a high level from the sun.
    Second, they didn’t report her weight. Out of thousands of patients I’ve recommended 5000 units of vitamin D for low levels, one very slim man went from below 32 ng. to 80 ng. in 6 months. He was in his 20’s, was 5’10”, and weighed 120 pounds. This is the largest increase I have seen. It is well known that body weight (fat content) is correlated with vitamin D levels.
    Third, in the days of antacids for ulcers, the “milk-alkali” syndrome was not uncommon. High calcium from large calcium intakes from antacids and milk intake. 2200 mg. of calcium is a termendous amount. It is much more likely that the calcium, and not the vitamin D, is primarily responsible for the elevated calcium level. (The determental effects of large amounts of calcium have been reported in the past few years.)

  3. Dan says:

    This case is anecdote. Too many unknowns to say anything.

  4. Dan says:

    One way to make sure you are not getting too many minerals or not enough is to measure urine pH using a pH test strip. Oddly pH test strips are controlled in the USA so you have have them shipped to a business address. The Macherey-Nagel ‘REF 921 20.3’ pH-Fix 4.5-10.00 color band strips are very good for urine testing (3-4 hours after you eat).

  5. Brant Cebulla says:

    Just found this paper by a vitamin D expert (Bischoff-Ferrari HA et al 2010) in another paper I was reading:


    “In 25 RCTs, mean serum calcium levels were not related to oral vitamin D up to 100,000 IU per day or achieved 25(OH)D up to 643 nmol/l. Mean levels of 75 to 110 nmol/l were reached in most RCTs with 1,800 to 4,000 IU vitamin D per day without risk.”