:Selenium:

:Selenium activates the antioxidant enzyme: glutathione peroxidase, which helps protect against aging and cancer. Yeast-derived selenium induces apoptosis (programmed cell death) in cancer cells in vitro and in animals. 1 2 3 A double-blind trial with over 1,300 people finds 200 mcg of yeast-source selenium per day for 4.5 years causes a 50% drop in cancer death rate. 4 A study finds men consuming the most dietary selenium (assessed indirectly by measuring toenail selenium) develop 65% fewer advanced prostate cancers than men with the lowest selenium intake. 5

Selenium is essential for healthy immune function. Selenium supplementation reduces incidence of viral hepatitis in selenium-deficient populations. 6 In a non-deficient elderly population, selenium supplementation stimulates activity of white blood cells. 7 Selenium is activates thyroid hormones.

In a double-blind trial, selenium supplementation of infertile men improves motility of sperm and increases chance of conception. 8

Sources: Brazil nuts are high in selenium. Yeast, whole grains, and seafood are also good. Animal studies find that selenium from yeast is better absorbed than inorganic selenite. 9

Science-supported-uses:

• Asthma
• Atherosclerosis
• Colon cancer (reduces risk)
• Depression
• Dermatitis herpetiformis
• Halitosis (if gum disease)
• Heart attack
• HIV support
• Immune function (for elderly people)
• Infections (to prevent hospital-acquired infections in very low birth weight infants)
• Infertility (male)
• Lung cancer (reduces risk)
• Pancreatic insufficiency
• Phenylketonuria (if deficient)
• Prostate cancer (reduces risk)
• Rheumatoid arthritis

Traditional clinical uses:

• Cardiac arrhythmia
• Cardiomyopathy (only for Keshan’s cardiomyopathy)
• Colon cancer
• Diabetic retinopathy (in combination with vitamin A ,vitamin C , and vitamin E )
• Hepatitis
• Hypothyroidism (if deficient)
• Liver cirrhosis
• Macular degeneration
• Osgood-Schlatter disease
• Pap smear (abnormal)
• Pre- and post-surgery health
• Retinopathy (combined with vitamin A ,vitamin C and vitamin E )

Deficiency: While most people probably don’t take in enough selenium, gross deficiencies are rare in Western countries. Soils in some areas are selenium-deficient and people who eat foods grown primarily on selenium-poor soils are at risk for deficiency. Breast cancer maps are nearly identical to maps of low soil selenium. People with AIDS have been reported to be depleted in selenium. 10 Similarly, limited research has reported an association between heart disease and depleted levels of selenium. 11 People who are deficient in selenium have an increased risk of developing certain types of rheumatoid arthritis .12

Dosage: The Recommended Dietary Allowance for most adults is 55 mcg per day, but an adult intake of 100 to 200 mcg of selenium is recommended by many doctors.

Side-effects: Selenium is safe at 100–200 mcg per day; over 900 mcg daily can cause adverse effects in some people. 13 Selenium toxicity can cause loss of fingernails, skin rash, and changes in the nervous system. In the presence of iodine-deficiency-induced goiter, selenium supplementation can exacerbate low thyroid. 14 The National Academy of Sciences recommends selenium intake not exceed 400 mcg per day, unless monitored by a health practitioner. 15

Selenium enhances the antioxidant effect of vitamin E. Selenium protects against mercury toxicity.

Drug interactions:

• Cisplatin (Side effect reduction/prevention) Clozapine (Depletion or interference)
• Oral Corticosteroids (Depletion or interference)
• Valproic Acid theoretically should be supported by adequate intakes of vitamin E and selenium.

References:

1. Lu J, Pei H, Ip C, et al. Effect on an aqueous extract of selenium-enriched garlic on in vitro markers and in vivo efficacy in cancer prevention. Carcinogenesis 1996;17:1903–7.
2. Wilson AC, Thompson HJ, Schedin PJ, et al. Effect of methylated forms of selenium on cell viability and the induction of DNA strand breakage. Biochem Pharmacol 1992;43:1137–41.
3. Redman C, Xu MJ, Peng YM, et al. Involvement of polyamines in selenomethionine induced apoptosis and mitotic alterations in human tumor cells. Carcinogenesis 1997;18:1195–202.
4. Clark LC, Combs GF, Turnbull BW, et al. Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin. JAMA 1996;276:1957–63. Published erratum appears in JAMA 1997;277:1520.
5. Yoshizawa K, Willett WC, Morris SJ, et al. Study of prediagnostic selenium levels in toenails and the risk of advanced prostate cancer. J Natl Cancer Inst 1998;90:1219–24.
6. Yu S-Y, Li W-G, Zhu Y-J, et al. Chemoprevention trial of human hepatitis with selenium supplementation in China. Biol Trace Element Res 1989;20:15–20.
7. Peretz A, Néve J, Desmedt J, et al. Lymphocyte response is enhanced by supplementation of elderly subjects with selenium-enriched yeast. Am J Clin Nutr 1991;53:1323–8.
8. Scott R, Macpherson A, Yates RWS, et al. The effect of oral selenium supplementation on human sperm motility. Br J Urol 1998;82:76–80.
9. Yoshida M, Fukunaga K, Tsuchita H, Yasumoto K. An evaluation of the bioavailability of selenium in high-selenium yeast. J Nutr Sci Vitaminol 1999;45:119–28.
10. Dworkin BM. Selenium deficiency in HIV infection and the acquired immunodeficiency syndrome (AIDS). Chem Biol Iteract 1994;91:181–6.
11. Moore JA, Noiva R, Wells IC. Selenium concentrations in plasma of patients with arteriographically defined coronary atherosclerosis. Clin Chem 1984;30:1171–3.
12. Knekt P, Heliovaara M, Aho K, et al. Serum selenium, serum alpha-tocopherol, and the risk of rheumatoid arthritis. Epidemiology 2000;11:402–5.
13. Yang GQ, Zhou RH. Further observations on the human maximum safe dietary selenium intake in a seleniferous area of China. J Trace Elem Electrolytes Hlth Dis 1994;8:159–65.
14. Contempre B, Dumont JE, Ngo B, et al. Effects of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: The possible danger of indiscriminate supplementation of iodine deficient subjects with selenium. J Clin Endocrinol Metabol 1991;73:213–5.
15. Panel on Dietary Antioxidants and Related Compounds, Food and Nutrition Board, Institute of Medicine, National Academy of Sciences. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. National Academy Press, Washington, D.C., 2000.