Post by Bob Johnson on Jun 28th, 2012 at 10:47pm
It would be wise to be aware of this material and discuss it with our doc.
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Re: WARNING-vitamin "D"
Reply #6 - May 28th, 2012 at 10:04am Lenny, I appreciate your posting this warning for it serves to illuminate a special problem with self-help group, like ours. We lack the education/experience to be aware of the full range of potential outcomes surrounding any treatment we choose to use--or to recommend to others. While docs and mfgs are shaped by law and ethics to give this information, it's too easy for us to not pay attention to this issue--nor to even know how/where we would find such material.
A related issue: side effects are not neat, 1:1, effects from using any particular med, dose, or technique. There are so many variables affecting whether a troubling side effect develops that the best any medical authority can do is to provide ranges of variables associated with the potential for a negative effect.
You can see this in the following material. There is useful guidance but no, "use this dose and it's O.K.; use this dose and it creates problems." BUT to not have any guidance leaves us flying blind.
================================
[Source is the National Institutes of Health, the major medical research organization of the USA.]
Source: START PRINTPAGEMultimedia File Viewing and Clickable Links are available for Registered Members only!! You need to
or 
END PRINTPAGE
Health Risks from Excessive Vitamin D
VITAMIN D TOXICITY CAN CAUSE NON-SPECIFIC SYMPTOMS SUCH AS ANOREXIA, WEIGHT LOSS, POLYURIA, AND HEART ARRHYTHMIAS. MORE SERIOUSLY, IT CAN ALSO RAISE BLOOD LEVELS OF CALCIUM WHICH LEADS TO VASCULAR AND TISSUE CALCIFICATION, WITH SUBSEQUENT DAMAGE TO THE HEART, BLOOD VESSELS, AND KIDNEYS [1]. The use of supplements of both calcium (1,000 mg/day) and vitamin D (400 IU) by postmenopausal women was associated with a 17% increase in the risk of kidney stones over 7 years in the Women's Health Initiative [65]. A serum 25(OH)D concentration consistently >500 nmol/L (>200 ng/mL) is considered to be potentially toxic [5].
Excessive sun exposure does not result in vitamin D toxicity because the sustained heat on the skin is thought to photodegrade previtamin D3 and vitamin D3 as it is formed [6]. In addition, thermal activation of previtamin D3 in the skin gives rise to various non-vitamin D forms that limit formation of vitamin D3 itself. Some vitamin D3 is also converted to nonactive forms [1]. Intakes of vitamin D from food that are high enough to cause toxicity are very unlikely. Toxicity is much more likely to occur from high intakes of dietary supplements containing vitamin D.
Long-term intakes above the UL increase the risk of adverse health effects [1] (Table 4). Most reports suggest a toxicity threshold for vitamin D of 10,000 to 40,000 IU/day and serum 25(OH)D levels of 500–600 nmol/L (200–240 ng/mL). While symptoms of toxicity are unlikely at daily intakes below 10,000 IU/day, the FNB pointed to emerging science from national survey data, observational studies, and clinical trials suggesting that even lower vitamin D intakes and serum 25(OH)D levels might have adverse health effects over time. THE FNB CONCLUDED THAT SERUM 25(OH)D LEVELS ABOVE APPROXIMATELY 125–150 NMOL/L (50–60 NG/ML) SHOULD BE AVOIDED, AS EVEN LOWER SERUM LEVELS (APPROXIMATELY 75–120 NMOL/L OR 30–48 NG/ML) ARE ASSOCIATED WITH INCREASES IN ALL-CAUSE MORTALITY, GREATER RISK OF CANCER AT SOME SITES LIKE THE PANCREAS, GREATER RISK OF CARDIOVASCULAR EVENTS, AND MORE FALLS AND FRACTURES AMONG THE ELDERLY. The FNB committee cited research which found that vitamin D intakes of 5,000 IU/day achieved serum 25(OH)D concentrations between 100–150 nmol/L (40–60 ng/mL), but no greater. Applying an uncertainty factor of 20% to this intake value gave a UL of 4,000 IU which the FNB applied to children aged 9 and older, with corresponding lower amounts for younger children.
Table 4: Tolerable Upper Intake Levels (ULs) for Vitamin D [1] Age Male Female Pregnancy Lactation {see at citation source}
==============================
Re: WARNING-vitamin "D"
Reply #6 - May 28th, 2012 at 10:04am Lenny, I appreciate your posting this warning for it serves to illuminate a special problem with self-help group, like ours. We lack the education/experience to be aware of the full range of potential outcomes surrounding any treatment we choose to use--or to recommend to others. While docs and mfgs are shaped by law and ethics to give this information, it's too easy for us to not pay attention to this issue--nor to even know how/where we would find such material.
A related issue: side effects are not neat, 1:1, effects from using any particular med, dose, or technique. There are so many variables affecting whether a troubling side effect develops that the best any medical authority can do is to provide ranges of variables associated with the potential for a negative effect.
You can see this in the following material. There is useful guidance but no, "use this dose and it's O.K.; use this dose and it creates problems." BUT to not have any guidance leaves us flying blind.
================================
[Source is the National Institutes of Health, the major medical research organization of the USA.]
Source: START PRINTPAGEMultimedia File Viewing and Clickable Links are available for Registered Members only!! You need to
or END PRINTPAGEHealth Risks from Excessive Vitamin D
VITAMIN D TOXICITY CAN CAUSE NON-SPECIFIC SYMPTOMS SUCH AS ANOREXIA, WEIGHT LOSS, POLYURIA, AND HEART ARRHYTHMIAS. MORE SERIOUSLY, IT CAN ALSO RAISE BLOOD LEVELS OF CALCIUM WHICH LEADS TO VASCULAR AND TISSUE CALCIFICATION, WITH SUBSEQUENT DAMAGE TO THE HEART, BLOOD VESSELS, AND KIDNEYS [1]. The use of supplements of both calcium (1,000 mg/day) and vitamin D (400 IU) by postmenopausal women was associated with a 17% increase in the risk of kidney stones over 7 years in the Women's Health Initiative [65]. A serum 25(OH)D concentration consistently >500 nmol/L (>200 ng/mL) is considered to be potentially toxic [5].
Excessive sun exposure does not result in vitamin D toxicity because the sustained heat on the skin is thought to photodegrade previtamin D3 and vitamin D3 as it is formed [6]. In addition, thermal activation of previtamin D3 in the skin gives rise to various non-vitamin D forms that limit formation of vitamin D3 itself. Some vitamin D3 is also converted to nonactive forms [1]. Intakes of vitamin D from food that are high enough to cause toxicity are very unlikely. Toxicity is much more likely to occur from high intakes of dietary supplements containing vitamin D.
Long-term intakes above the UL increase the risk of adverse health effects [1] (Table 4). Most reports suggest a toxicity threshold for vitamin D of 10,000 to 40,000 IU/day and serum 25(OH)D levels of 500–600 nmol/L (200–240 ng/mL). While symptoms of toxicity are unlikely at daily intakes below 10,000 IU/day, the FNB pointed to emerging science from national survey data, observational studies, and clinical trials suggesting that even lower vitamin D intakes and serum 25(OH)D levels might have adverse health effects over time. THE FNB CONCLUDED THAT SERUM 25(OH)D LEVELS ABOVE APPROXIMATELY 125–150 NMOL/L (50–60 NG/ML) SHOULD BE AVOIDED, AS EVEN LOWER SERUM LEVELS (APPROXIMATELY 75–120 NMOL/L OR 30–48 NG/ML) ARE ASSOCIATED WITH INCREASES IN ALL-CAUSE MORTALITY, GREATER RISK OF CANCER AT SOME SITES LIKE THE PANCREAS, GREATER RISK OF CARDIOVASCULAR EVENTS, AND MORE FALLS AND FRACTURES AMONG THE ELDERLY. The FNB committee cited research which found that vitamin D intakes of 5,000 IU/day achieved serum 25(OH)D concentrations between 100–150 nmol/L (40–60 ng/mL), but no greater. Applying an uncertainty factor of 20% to this intake value gave a UL of 4,000 IU which the FNB applied to children aged 9 and older, with corresponding lower amounts for younger children.
Table 4: Tolerable Upper Intake Levels (ULs) for Vitamin D [1] Age Male Female Pregnancy Lactation {see at citation source}