Integrating Dietary Supplements Into Cancer Care
Integr Cancer Ther September 2013 vol. 12 no. 5 369-384
Moshe Frenkel, MD1,2,*
Donald I. Abrams, MD3
Elena J. Ladas, MS, RD4
Gary Deng, MD5
Mary Hardy, MD6
Jillian L. Capodice, LAC, MS7
Mary F. Winegardner, PA-C, MPAS8
J. K. Gubili, MS5
K. Simon Yeung, PharmD, MBA, LAc5
Heidi Kussmann, ND, FABNO9
Keith I. Block, MD10
1University of Texas, Houston, TX, USA
2Oncology Institute, Meir Medical Center, Kfar Saba, Israel
3San Francisco General Hospital, San Francisco, CA, USA
4Columbia University, New York, NY, USA
5Memorial Sloan-Kettering Cancer Center, New York, NY, USA
6Simms/Mann UCLA Center for Integrative Oncology, Los Angeles, CA, USA
7Columbia University Medical Center, New York, NY, USA
8Integrative Medicine Consultants, Clear Lake, IA, USA
9Cancer Treatment Centers of America, Tulsa, OK, USA
10Block Center for Integrative Cancer Treatment, Skokie, IL, USA
Moshe Frenkel, Integrative Oncology Consultants, Hashoftim 1B, Zichron Yaacov 30900, Israel. Email: frenkelm at netvision.net.il
Many studies confirm that a majority of patients undergoing cancer therapy use self-selected forms of complementary therapies, mainly dietary supplements. Unfortunately, patients often do not report their use of supplements to their providers. The failure of physicians to communicate effectively with patients on this use may result in a loss of trust within the therapeutic relationship and in the selection by patients of harmful, useless, or ineffective and costly nonconventional therapies when effective integrative interventions may exist. Poor communication may also lead to diminishment of patient autonomy and self-efficacy and thereby interfere with the healing response. To be open to the patient’s perspective, and sensitive to his or her need for autonomy and empowerment, physicians may need a shift in their own perspectives. Perhaps the optimal approach is to discuss both the facts and the uncertainty with the patient, in order to reach a mutually informed decision. Today’s informed patients truly value physicians who appreciate them as equal participants in making their own health care choices. To reach a mutually informed decision about the use of these supplements, the Clinical Practice Committee of The Society of Integrative Oncology undertook the challenge of providing basic information to physicians who wish to discuss these issues with their patients. A list of leading supplements that have the best suggestions of benefit was constructed by leading researchers and clinicians who have experience in using these supplements.
This list includes curcumin, glutamine, vitamin D, Maitake mushrooms, fish oil, green tea, milk thistle, Astragalus, melatonin, and probiotics. The list includes basic information on each supplement, such as evidence on effectiveness and clinical trials, adverse effects, and interactions with medications. The information was constructed to provide an up-to-date base of knowledge, so that physicians and other health care providers would be aware of the supplements and be able to discuss realistic expectations and potential benefits and risks.
PDF is attached at the bottom of this page
Vitamin D (extracted from PDF)
Background
Vitamin D is a vitamin with hormone-like action that controls calcium, phosphorus, and bone metabolism. It is the only vitamin that the body can manufacture from sunlight. An increasing proportion of the world's population is becoming deficient in vitamin D because of indoor living, clothing customs, heliophobia, and sunscreen use.50 The first suggestion that vitamin D was related to cancer risk came from an observation that colon cancer mortality rates were lower in the southwestern United States compared with the northeast.51,52 Subsequent studies have supported the finding that lower serum 25-hydroxyvitamin D levels are associated with increased risks of breast and prostate as well as colorectal and possibly other cancers, although the data are considered inconclusive.53-55 An increasing body of evidence suggests that lower serum levels are also related with poorer prognoses in patients diagnosed with various malignancies.52
Mechanism of Action in Cancer Care and Clinical Trials
The mechanistic explanation for the protection of vitamin D and its metabolites against cancer is unclear at present but an area of tremendous ongoing research. The 25-hydroxyvitamin D metabolite, 1, 25-dihydroxyvitamin D, is the biologically active moiety that works through the vitamin D receptor to regulate gene transcription.51,56,57 Administration of vitamin D analogues produce antiprolif-erative effects, can activate apoptotic pathways, and inhibit angiogenesis. Additional benefits of vitamin D may be by way of enhancing of the anticancer effects of cytotoxic agents. Other chemoprotective mechanisms by which vitamin D may work include enhancing DNA repair, antioxi-dant protection, and immunomodulation. One randomized trial of calcium and vitamin D conducted in Nebraska demonstrated that supplementation reduces all-cancer risk in postmenopausal women.58 A meta-analysis that included 2 additional randomized studies suggested that high dose (1000 IU/d) vitamin D supplementation can not only reduce the risk of total cancer but also found that higher 25-hydroxyvitamin D concentrations might be associated with increased risk of cancer.59
Safety and Side Effects
Vitamin D supplementation is generally safe with few side effects, most commonly gastrointestinal. In one large study of vitamin D and calcium supplementation, an increased risk of renal and urinary stones was noted.59 Excess vitamin D supplementation can lead to hypercalcemia.50
Dosage
Measurement of serum 25-hydroxyvitamin D level should guide dosing.60 The Institute of Medicine guideline that a level greater than 20 ng/mL is adequate for maintaining bone health may not be appropriate in the care of patients with malignant diagnoses although conclusive evidence of the optimal 25-hydroxyvitamin D level in these patients is lacking.61 A safe recommendation would be to achieve a 25-hydroxyvitamin D level in the 40 to 80 ng/mL range. Although some food products (eggs, fortified dairy, mushrooms, and fish) may provide small amounts of vitamin D2 (ergocalciferol), ultraviolet light from the sun is the best source of vitamin D3 (cholecalciferol), but its production is impaired with age, obesity, and pigmentation. Hence, oral supplementation is advised. Vitamin D is a fat-soluble vitamin, so a liquid or gel-bead preparation will lead to maximal absorption. In severe deficiency, each 1000 IU dose increment should increase 25-hydroxyvitamin D levels by 10 ng/mL, decreasing as optimal levels are achieved.62
Interactions
There are no reported interactions between vitamin D supplements and individual antineoplastic agents.63 Vitamin D is metabolized by the cytochrome P450 hepatic enzyme system so theoretical interactions are possible. Concurrent use with bisphosphonates may have added benefit in increasing bone density. Through its immunomodulatory effects, vitamin D could theoretically interfere with immunosuppressants.