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I stumbled on one of the growing number of local media stories on the power of vitamin D. \nIn one story, a purported "expert" was talking about the benefits of "high-dose" vitamin D, meaning up to 1000, even 2000 units per day. \nI regard this as high-dose---for an infant. \nJudging by my experiences, now numbering well over 1000 patients over three years time, I'd regard this dose range not as "high dose," nor moderate dose, perhaps not even low dose. I'd regard it as barely adequate.

Twice single doses of 100,000 IU of vitamin D in winter is adequate and safe for prevention of vitamin D deficiency in healthy children from Ushuaia, Tierra Del Fuego, Argentina. Tau C, Ciriani V, Scaiola E, Acuña M. J Steroid Biochem Mol Biol. 2007 Mar;103(3-5):651-4. Epub 2007 Jan 25. PMID: 17257830 doi:10.1016/j.jsbmb.2006.12.027 These results disclosed that to prevent vitamin D deficiency for children at zones of risk at the south of our country, double supplementation of 100,000 IU of vitamin D during autumn and winter, would be adequate and safe.

Effectiveness and safety of vitamin D in relation to bone health. Cranney A, Horsley T, O'Donnell S, Weiler H, Puil L, Ooi D, Atkinson S, Ward L, Moher D, Hanley D, Fang M, Yazdi F, Garritty C, Sampson M, Barrowman N, Tsertsvadze A, Mamaladze V. Evid Rep Technol Assess (Full Rep). 2007 Aug;(158):1-235. Review. PMID: 18088161 CONCLUSIONS: The results highlight the need for additional high quality studies in infants, children, premenopausal women, and diverse racial or ethnic groups. There was fair evidence from studies of an association between circulating 25(OH)D concentrations with some bone health outcomes (established rickets, PTH, falls, BMD). However, the evidence for an association was inconsistent for other outcomes (e.g., BMC in infants and fractures in adults). It was difficult to define specific thresholds of circulating 25(OH)D for optimal bone health due to the imprecision of different 25(OH)D assays. Standard reference preparations are needed so that serum 25(OH)D can be accurately and reliably measured, and validated. In most trials, the effects of vitamin D and calcium could not be separated. Vitamin D(3) (>700 IU/day) with calcium supplementation compared to placebo has a small beneficial effect on BMD, and reduces the risk of fractures and falls although benefit may be confined to specific subgroups. Vitamin D intake above current dietary reference intakes was not reported to be associated with an increased risk of adverse events. However, most trials of higher doses of vitamin D were not adequately designed to assess long-term harms.

Effectiveness and safety of vitamin D in relation to bone health. Cranney A, Horsley T, O'Donnell S, Weiler H, Puil L, Ooi D, Atkinson S, Ward L, Moher D, Hanley D, Fang M, Yazdi F, Garritty C, Sampson M, Barrowman N, Tsertsvadze A, Mamaladze V. Evid Rep Technol Assess (Full Rep). 2007 Aug;(158):1-235. Review. PMID: 18088161 CONCLUSIONS: The results highlight the need for additional high quality studies in infants, children, premenopausal women, and diverse racial or ethnic groups. There was fair evidence from studies of an association between circulating 25(OH)D concentrations with some bone health outcomes (established rickets, PTH, falls, BMD). However, the evidence for an association was inconsistent for other outcomes (e.g., BMC in infants and fractures in adults). It was difficult to define specific thresholds of circulating 25(OH)D for optimal bone health due to the imprecision of different 25(OH)D assays. Standard reference preparations are needed so that serum 25(OH)D can be accurately and reliably measured, and validated. In most trials, the effects of vitamin D and calcium could not be separated. Vitamin D(3) (>700 IU/day) with calcium supplementation compared to placebo has a small beneficial effect on BMD, and reduces the risk of fractures and falls although benefit may be confined to specific subgroups. Vitamin D intake above current dietary reference intakes was not reported to be associated with an increased risk of adverse events. However, most trials of higher doses of vitamin D were not adequately designed to assess long-term harms.

Consumption vitamin C is more than 1000 mg per day can causes nausea, gastrointestinal upset, stomach cramps, diarrhea and kidney stones.

Changes of terminal cancer patients' health-related quality of life after high dose vitamin C administration.\nYeom CH, Jung GC, Song KJ.\nJ Korean Med Sci. 2007 Feb;22(1):7-11.\nPMID: 17297243

Are there any side effects from the consumption of vitamin C supplement much more than the recommended dosage?

The controversial place of vitamin C in cancer treatment. Verrax J, Calderon PB. Biochem Pharmacol. 2008 Dec 15;76(12):1644-52. Epub 2008 Sep 30. Review. PMID: 18938145 doi:10.1016/j.bcp.2008.09.024    

Intravenous vitamin C as a chemotherapy agent: a report on clinical cases.\nRiordan HD, Riordan NH, Jackson JA, Casciari JJ, Hunninghake R, González MJ, Mora EM, Miranda-Massari JR, Rosario N, Rivera A.\nP R Health Sci J. 2004 Jun;23(2):115-8.\nPMID: 15377059

Intravenously administered vitamin C as cancer therapy: three cases.\nPadayatty SJ, Riordan HD, Hewitt SM, Katz A, Hoffer LJ, Levine M.\nCMAJ. 2006 Mar 28;174(7):937-42.\nPMID: 16567755 \ndoi:10.1503/cmaj.050346.

Vitamin C and cancer revisited. Frei B, Lawson S. Proc Natl Acad Sci U S A. 2008 Aug 12;105(32):11037-8. Epub 2008 Aug 5. PMID: 18682554

Pharmacologic doses of ascorbate act as a prooxidant and decrease growth of aggressive tumor xenografts in mice. Chen Q, Espey MG, Sun AY, Pooput C, Kirk KL, Krishna MC, Khosh DB, Drisko J, Levine M. Proc Natl Acad Sci U S A. 2008 Aug 12;105(32):11105-9. Epub 2008 Aug 4. PMID: 18678913 doi: 10.1073/pnas.0804226105

Ascorbate in pharmacologic concentrations selectively generates ascorbate radical and hydrogen peroxide in extracellular fluid in vivo.\nChen Q, Espey MG, Sun AY, Lee JH, Krishna MC, Shacter E, Choyke PL, Pooput C, Kirk KL, Buettner GR, Levine M.\nProc Natl Acad Sci U S A. 2007 May 22;104(21):8749-54. Epub 2007 May 14.\nPMID: 17502596 \n doi: 10.1073/pnas.0702854104\n

Phase I clinical trial of i.v. ascorbic acid in advanced malignancy. Hoffer LJ, Levine M, Assouline S, Melnychuk D, Padayatty SJ, Rosadiuk K, Rousseau C, Robitaille L, Miller WH Jr. Ann Oncol. 2008 Nov;19(11):1969-74. Epub 2008 Jun 9. Erratum in: Ann Oncol. 2008 Dec;19(12):2095. PMID: 18544557 doi:10.1093/annonc/mdn377

A pilot clinical study of continuous intravenous ascorbate in terminal cancer patients. Riordan HD, Casciari JJ, González MJ, Riordan NH, Miranda-Massari JR, Taylor P, Jackson JA. P R Health Sci J. 2005 Dec;24(4):269-76. PMID: 16570523

Pharmacologic ascorbic acid concentrations selectively kill cancer cells: action as a pro-drug to deliver hydrogen peroxide to tissues. Chen Q, Espey MG, Krishna MC, Mitchell JB, Corpe CP, Buettner GR, Shacter E, Levine M. Proc Natl Acad Sci U S A. 2005 Sep 20;102(38):13604-9. Epub 2005 Sep 12. PMID: 16157892