Vitamin and Mineral Safety 2 nd Edition (2004)

Document Sample
Vitamin and Mineral Safety 2 nd Edition (2004) Powered By Docstoc
					    Vitamin and Mineral Safety
        2nd Edition (2004)

              John Hathcock, Ph.D.
 Vice President, Scientific and International Affairs
         Council for Responsible Nutrition
                  Washington, DC


CRN, Washington, DC   Vitamin and Mineral Safety, 2nd Edition   1
                       Objective
• To identify the highest chronic daily
  supplemental intakes of vitamins and minerals
  that can be confidently asserted to pose no risk
  of adverse effects for nearly everyone in the
  healthy adult population.
• (Note: The values identified do not represent
  recommended intakes.)



 CRN, Washington, DC    Vitamin and Mineral Safety, 2nd Edition   2
           Major Characteristics
• Quantitative evaluation by Risk Assessment
  procedure
• Scientific evidence on dose-response relationship of
  nutrients to adverse effects
• Addresses supplemental amounts of nutrients
• Uses accepted scientific methodology
• Uses Observed Safe Level (OSL), if possible, where
  data do not support NOAEL or LOAEL
• Scientific conclusions set in a practical framework
• International comparisons gives global utility
  CRN, Washington, DC   Vitamin and Mineral Safety, 2nd Edition   3
                    CRN Method
• Identifies Upper Level for Supplements (ULS) by
   – UL method when a NOAEL or LOAEL can be identified
   – Observed Safe Level (OSL), where no NOAEL or LOAEL
• Direct approach using supplemental data, where possible
• Difference approach when direct method is not possible
• Conservative selection of data, justifying Uncertainty Factor
  (UF) of 1.0, i.e., no additional correction for uncertainty




  CRN, Washington, DC       Vitamin and Mineral Safety, 2nd Edition   4
 WHY USE RISK ASSESSMENT?
• Valid and internationally accepted scientific basis for
  decisions related to safety
• Help avoid harm from excessive intakes
• Advice to the public about safety of high intakes
• Establish regulatory maximums for manufactured
  products—established to help avoid harm from
  consumption of toxic excesses
• Objective standard for international trade, consistent
  with WTO (SPS) obligations

  CRN, Washington, DC   Vitamin and Mineral Safety, 2nd Edition   5
            WHY NOT USE
          RDA-BASED LIMITS?
• RDA are not defined or identified to address safety
• Not valid as an indicator of safety
• RDA limit may preclude benefits at higher intake levels (e.g.,
  chromium, folic acid, selenium)
• Cannot be applied to substances without RDA values
• Disproportionately restrictive, compared with high intakes
  from certain conventional foods (e.g., B12 in liver)
• Rejected by Codex (CCNFSDU) in 2003
• Labeling, not limits, can address proper use


   CRN, Washington, DC       Vitamin and Mineral Safety, 2nd Edition   6
        CHANGES in                   2 nd   Edition
• All values apply to supplemental intakes only (ULS), not totals
• Increased values: 4 nutrients (vitamins D, E, C, and B1)
• Decreased values: 5 nutrients (vitamins K and B6, magnesium,
  iodine, iron)—note: iron is only marginally lower
• Newly evaluated: 3 nutrients (potassium, boron, fluoride)




  CRN, Washington, DC       Vitamin and Mineral Safety, 2nd Edition   7
Important Differences Among Reviews
                      FNB, EC SCF, UK EVM, and CRN
 •   Vitamin A: UK sets value on bone effects; others on birth defects
 •   Vitamin D: CRN uses same data as FNB, but gains confidence from later data used
     by SCF
 •   Vitamin E: CRN directly uses clinical trial data
 •   Nicotinic acid: In contrast to others, CRN does not consider flushing to be “hazard”
 •   B6: International disagreement and confusion; CRN value same as by FNB but on
     somewhat different basis
 •   B12: CRN OSL method identifies 3,000 mcg; UK value is 2,000 mcg; others do not
     find “hazard” and do not set value
 •   Calcium: CRN and UK values for supplements; others for totals
 •   Chromium: CRN directly uses clinical trial data; EVM extrapolates from animal
     data; FNB and EC did not set values
 •   Selenium: CRN’s lower value is for supplements, not totals, and the difference is
     less that it appears


     CRN, Washington, DC               Vitamin and Mineral Safety, 2nd Edition       8
 FUTURE: Vitamins and Minerals
• Urge Food and Nutrition Board to expand the
  UL method to include the OSL concept
• Urge Codex, EC and national authorities to
  developed internationally accepted UL values
  – Based on CRN modifications of UL method




 CRN, Washington, DC        Vitamin and Mineral Safety, 2nd Edition   9
 FUTURE: Non-essential nutrients
Apply expanded UL method to safety evaluation
• Other nutrients (e.g., amino acids, fatty acids)
• Vitamin-like substances in diet (e.g., lutein,
  lycopene, etc.)
• Metabolites in physiology and/or diet (e.g.,
  carnitine, creatine, Co Q10, etc.)
• Complex materials (botanical ingredients and
  extracts, e.g., garlic, ginkgo, ginseng, etc.)
 CRN, Washington, DC   Vitamin and Mineral Safety, 2nd Edition   10
                 Conclusions
• Risk assessment is only rational basis to identify need
  for and size of limits for nutrients in supplements
• UL method is appropriate but should be expanded to
  include OSL concept
• Safety data available on supplemental amounts of
  many nutrients, and thus ULS can be derived directly
• Strong disagreements between FNB, EC SCF (now
  EFSA) and UK EVM on some nutrients show need for
  international agreements on safety values
• CRN approach and outcomes provide good example of
  science-based safety evaluation in practical setting
 CRN, Washington, DC   Vitamin and Mineral Safety, 2nd Edition   11

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:27
posted:11/30/2011
language:English
pages:11