Vitamin D Supplementation, MS Patients and Hypercalcemia

Patient Expert

During winter months when the skies are gray and the ground is wet, our bodies do not have as much opportunity to transform sunlight into vitamin D.   During summer months, our exposed skin works to transform sunshine into the hormone we know as vitamin D.   20 minutes of full-body UV-B sun exposure for a light-skinned person produces at least 10,000IU (international units) of vitamin D.   I don't know about you, but I'm a bit reluctant to sunbathe for 20 minutes when it's only 34 degrees outside.

Add a diagnosis of multiple sclerosis and it becomes even more important to make sure that you get enough vitamin D through sunlight, food, and/or supplementation.   The connection between vitamin D deficiency and MS susceptibility, as well as increased disease activity, has been studied in great detail in recent years.   The evidence of this connection has contributed to the mainstream practice of neurologist's prescribing or recommending D supplementation (calciferol or cholecalciferol) to MS patients.

How much D should an MS patient take?   1000IU daily?   5000IU daily?   50,000IU weekly?   Is it really necessary?

The amount of vitamin D an MS patient should take is highly dependent upon his/her current serum levels or low-D deficiency as determined by the 25-hydroxyvitamin D (25-OH-D) blood test.   In the general population, a serum result is consider adequate if it is above 30 ng/mL (or 75 nm/L).   However, many neurologists (my own included) recommend that their patients maintain a 25-OH-D level above 50 ng/mL (up to 80 ng/mL).

When I was initially tested for a suspected vitamin D deficiency, my serum level was 7.8 ng/mL which is practically non-existent   I was having a lot of pain, including very tender bones and achy muscles.   In fact, my bones almost felt "squishy" when squeezed.   Vitamin D, in conjunction with Calcium, is necessary to maintain bone density.   It took two years, close monitoring, and certain experimentation to find the amount of supplementation I needed to raise my serum levels from 7.8 ng/mL to 61 ng/mL.

The amount of supplementation you might need to take varies upon your age, body weight, BMI, skin pigmentation, the season, and amount of sun exposure.   I have a larger BMI and do not get much direct sun exposure.   To maintain a current serum level of 68 ng/mL, I take 10,000IU daily of vitamin D3 which is an amount considered to be safe based on various studies using even higher levels.   (see Hathcock JN, Shao A, Vieth R, Heaney R. Risk assessment for vitamin D. Am J Clin Nutr. 2007;85(1):6-18.)

Please note that you should consult with your doctor and be tested before beginning supplementation or altering current supplementation.   Your needs will vary depending upon your current situation.

One concern with taking higher levels of vitamin D, with or without extra calcium, is the development of a condition called hypercalcemia.   In a new case study published in the January 2012 edition of Archives of Neurology, researchers share that "overexposure to vitamin D produces symptomatic hypercalcemia, with possible weakness, fatigue, depression, confusion, stupor or coma, polyuria, nephrolithiasis, renal failure, ectopic calcification, conjunctivitis, fever, chills, anorexia, nausea, vomiting, and constipation."   (see Marcus JF, Shaley SM, etc. Severe Hypercalcemia Following Vitamin D Supplementation in a Patient With Multiple Sclerosis: A Note of Caution. Arch Neurol. 2012;69(1):129-132.)

A 58-year-old woman living with progressive MS (diagnosed in 2001), hypertension, and osteoporosis (diagnosed in 2003) showed up at the hospital emergency department with face and arm tremors and had had difficulty speaking for the previous two hours.   She also had experienced a gradual decline during the previous two weeks, characterized by difficulty with wheelchair transfers, impaired balance, abdominal discomfort, decreased appetite, and lethargy.   Based on a 25-OH-D serum level of 33.7 ng/mL in March 2009, this patient began taking 5000IU of vitamin D in addition to the 500IU found her in multi-vitamin tablet.   She was also taking 2020 mg of calcium daily.

Six months before she showed up in the ER, her 25-OH-D serum level was 83 ng/mL and her serum calcium level was 9.5 mg/dL (which is well within normal limits).   At the time of ER admission, her 25-OH-D serum level was 103 ng/mL and her serum calcium level of 15.2 mg/dL (normal range 8.7-10.1 mg/dL).   The MS patient received four liters of normal saline for rehydration, together with magnesium and phosphorus to replete deficient levels.   Researchers report that "after two to three hours, her tremors resolved and her language function recovered.   Serum calcium levels and renal function promptly returned to normal after rehydration.   The patient was amnestic [with no memory] for the entire period during which she had tremors and aphasia."

Although 5,500IU daily supplementation is generally considered within a safe level, this MS patient's experience emphasizes the importance of remaining vigilant in monitoring blood serum levels.   Researchers suggest that "possible reasons for our patient's adverse response include her prolonged use of both high-dose cholecalciferol and calcium supplementation (for two years), her ingestion of almost twice the amount of elemental calcium taken by many patients, immobility, medication interactions, or her unique metabolism."

This isolated case is rather unusual and not typical of the majority of MS patients.   The only way to know what is safe for YOU is to talk with your doctor.

When was the last time your vitamin D serum levels were checked?   How often does your neurologist (or primary care doctor) order tests for complete blood counts and chemistry?

My blood counts/chemistry is tested every two months since I take methotrexate and my 25-OH-D serum levels have been checked every five to six months during the past four years.   My calcium serum levels have ranged between 8.9 and 9.8 mg/dL during the same time period (normal reference range 8.6-10.4 mg/dL).