Vitamin D Levels Impact Myeloma Patient Outcomes After Transplant

The Myeloma Crowd published a post a few months ago summarizing a study that indicated the benefit of ‘normal’ Vitamin D levels in circulating plasma on the outcomes of autologous stem cell transplant for myeloma patients. The journal Hematological Oncology has just published the results of a Swiss study that provides additional confirmation that appropriate levels of Vitamin D have a beneficial impact on disease progression of multiple myeloma patients after auto-SCT.

There have been a number of publications that have reported that patients with hematological malignancies undergoing allo-SCT have typically fared better in both Overall Survival (OS) and Progression Free Survival (PFS) when their Vitamin D levels were at normal or above normal levels. There is precious little literature available, though, about the impact normal Vitamin D levels have on OS and PFS of patients undergoing auto-SCT’s. The paper referenced above provides outcomes of a six-year study that tracked patients through their treatment journey from diagnosis to post auto-SCT. The results for myeloma patients are worth noting and being aware of:

• In the myeloma patients [median] PFS was longer in the normal VitD patients as compared to the low VitD patients (median 19.5 months vs. 16.0 months).’
• Median OS [of myeloma patients] was 21.4 months in patients with normal VitD as compared to 20.4 months in patients with low VitD.’

You may look at these comparisons and say, ‘Big whoop ! I don’t see much of a difference.’ Technically you are somewhat correct, but I encourage you to click on the above referenced link and look at the Kaplan-Meier curves for the myeloma group (right hand side, top of page 5 of the article) and you will see how the OS and PFS curves diverge rapidly for the two different Vitamin D patient groups. For example, mortality in the first two years of treatment was near 0 % in the normal Vitamin D group and ran about 20 % in the low Vitamin D group.

The authors make several comments worth noting :

• … VitD levels were demonstrated to have an independent prognostic impact on overall survival [with a degree of certainty of + 98 %]. With the increase of VitD levels by one unit (nmol/L), the risk of death was reduced by 2 %.’
• It is tempting to correct low VitD levels [before auto-SCT], particularly since this is an easy and inexpensive intervention with a favorable toxicity profile.’

A final note for those who choose to read the article and then compare their own Vitamin D lab results against what is considered ‘normal’ in this article. The authors use a measure of Vitamin D levels expressed as nmol/L (nano moles per liter). This is how Vitamin D results are typically expressed in Europe and their cut-off point between low and normal levels is 52 nmol/L. Vitamin D results in the US are typically expressed as ng/mL (nano-grams per milliliter) with a standard range of 30-100 ng/ml (<10 ng/ML is deficiency, 10-30 ng/ml is insufficiency, 30-100 ng/mL is sufficiency, >100 mL is toxicity). I have therefore two items of caution:

• You cannot start to blindly compare your ownVitamin D lab results expressed in ng/mL to this European cutoff point expressed in nmol/L. You need to work this through with your physician.
• Please do not rush to Costco to buy this gallon jug of Vitamin D capsules and start popping them like candy. Vitamin D is not cleared out of the body as rapidly as other vitamins like Vitamin C. Vitamin D builds up and there is a point where it becomes toxic to humans. I am sure that when your physician prescribes a course of Vitamin D treatment, he/she will also monitor several times per year that you will remain within a healthy, acceptable range of Vitamin D in your plasma.