Discussion in 'General Discussion' started by Jason, Nov 29, 2007.
Much cheaper to given 25OHD3. Standard here is 50,000 IU a month though I go higher than this.
Types of Vitamin D:
· D2 (Ergosterol, Ergocalciferol#)
· D3 (7-Dehydrocholesterol, Previtamin D3, Cholecalciferol, 25-hydroxycholecalciferol, Calcitriol (1,25-dihydroxycholecalciferol), Calcitroic acid)
· D4 (Dihydroergocalciferol)
· D5 · D analogues (Alfacalcidol, Dihydrotachysterol, Calcipotriol, Tacalcitol, Paricalcitol)
... from Wikipedia.
Alfacalcidol (or 1-hydroxycholecalciferol) is an analogue of vitamin D used for supplementation in humans and as a poultry feed additive.
Alfacalcidol has a weaker impact on calcium metabolism than calcitriol, while having more potent effects on parathyroid hormone levels and the immune system, including regulatory T cells. It is considered[by whom?] to be a more useful form of vitamin D supplementation, mostly due to much longer half-life and lower kidney load.
Used as a poultry feed additive, it prevents tibial dyschondroplasia and increases phytate bioavailability.
For Vitamin D testing through 25-OH-Vitamin D3, if someone was taking Alfacalcidol, would their 25-OH-Vitamin D3 levels go up ?
Can't see why it should since you're dosing with 1-OH analogue.
New low in Media reporting of Medical issues.
Results: The offspring had significantly lower levels of vitamin D (64.3 nmol/L) compared with controls (68.4 nmol/L; p = 0.002), independent of possible confounding factors.
I think they mean insignificant !!! or statistically significant, practically irrelevant.
I got this lab test back on a 92 year old with some renal insufficiency via the Nephrologist.
25-hydroxy vitamin D 103 (75-250).
1,25-hydroxy Vitamin D 137 (30-120).
Calcitriol Pharmacological Properties and Effects
Calcitriol is one of the most important active metabolites of vitamin D3. It is normally formed
in the kidney from its precursor, 25-hydroxycholecalciferol (25-HCC)
Q: Why check 1,25-hydroxy Vitamin D (aka Calcitriol) levels ?
A: Because it is the active form of Vitamin D.
Maybe the better question is why check 25-hydroxy Vitamin D ? Is it cheaper ?
I'm not sure why one would check 1,25- except perhaps to see if there is enough renal tissue doing the conversion.
One checks 25-OH because 1,25 levels don't relate to insufficiency. As levels of 25-OH drop, there is compensatory increased 1,25 conversion so high levels can actually indicate deficiency.
I guess sarcoid and other granulomatous conditions might increase 1,25 as well.
I was reading my vitamin D notes from a few years ago.
[Random Vitamin D exerts]
because tissues are able to synthesize 1,25 locally in their microenvirionment
and high levels of 1,25 to achieve the same effect cause calcium toxicity
and the high PTH that results, causes osteoporosis.
There is no single target level of serum 25-hydroxyvitamin D [25(OH)D] acceptable to all physicians, but Dr. Bikle defends the target of 80 nmol/L or the equivalent of 32 ng/mL.
25-(OH)-D Level ng/ml(used in USA) = nMol/L (international)
2.5 ng/ml = 1 nMol/L
Vitamin D supplement Over 400 IU - NNT 93, hip# 168.
Vitamin D 800-1000IU NNT 15 (7% reduction)
Total Mortality - NNT 147,
Pregnancy - 50% premature births
400IU, 2,000-4,000 IU
Women taking 400 IU/day, as exists in prenatal vitamins, had double the pregnancy complications of the women taking 4,000 IU/day.
sun - SPF 30, 99% reduction in Vitamin D.
100% skin exposed, white, 1,000 IU in 5 min, summer (10am-2pm).
Most of us make about 20,000 IU of vitamin D after about 20 minutes of summer sun. (full body exposure).
Generally recommend about 10 mins per day of face and arms exposure.
PTH 9.3 - Note: high levels of PTH drive 25 to 1,25 conversion.
1,25-dihyroxycolecalciferol (most active form)(don't order)(or 1,25-OH - VitD) ==> order 25-OH-VitD.
Yeah ... what does this slight difference mean if anything.
Vitamin D status and ill health: a systematic review
Prof Philippe Autier MD a b Corresponding AuthorEmail Address, Prof Mathieu Boniol PhD a b, Cécile Pizot MSc a, Prof Patrick Mullie PhD a c
Low serum concentrations of 25-hydroxyvitamin D (25[OH]D) have been associated with many non-skeletal disorders. However, whether low 25(OH)D is the cause or result of ill health is not known. We did a systematic search of prospective and intervention studies that assessed the effect of 25(OH)D concentrations on non-skeletal health outcomes in individuals aged 18 years or older. We identified 290 prospective cohort studies (279 on disease occurrence or mortality, and 11 on cancer characteristics or survival), and 172 randomised trials of major health outcomes and of physiological parameters related to disease risk or inflammatory status. Investigators of most prospective studies reported moderate to strong inverse associations between 25(OH)D concentrations and cardiovascular diseases, serum lipid concentrations, inflammation, glucose metabolism disorders, weight gain, infectious diseases, multiple sclerosis, mood disorders, declining cognitive function, impaired physical functioning, and all-cause mortality. High 25(OH)D concentrations were not associated with a lower risk of cancer, except colorectal cancer. Results from intervention studies did not show an effect of vitamin D supplementation on disease occurrence, including colorectal cancer. In 34 intervention studies including 2805 individuals with mean 25(OH)D concentration lower than 50 nmol/L at baseline supplementation with 50 μg per day or more did not show better results. Supplementation in elderly people (mainly women) with 20 μg vitamin D per day seemed to slightly reduce all-cause mortality. The discrepancy between observational and intervention studies suggests that low 25(OH)D is a marker of ill health. Inflammatory processes involved in disease occurrence and clinical course would reduce 25(OH)D, which would explain why low vitamin D status is reported in a wide range of disorders. In elderly people, restoration of vitamin D deficits due to ageing and lifestyle changes induced by ill health could explain why low-dose supplementation leads to slight gains in survival. [source]
I haven't had a chance to read this, but this commentary popped into my letter box
Interesting to see the large clinical trials underway.
2,000 IU/day in the USA study seems a bit on the conservative side.
A 2,000 vs 4,000 IU/day study might yield better data ?
I'm not as interested in the Vitamin D link to CAD, strokes, or cancer.
I'm interested in the effects on autoimmune disorders.
I've been to talks from Mark Bolland, and I'm not convinced. As Veith says, the higher doses data isn't there yet, and that's what I tend to use over the last decade or so.
A Predictive Equation to Guide Vitamin D Replacement Dose in Patients
Background. Vitamin D is essential for bone health and probably the health of most nonskeletal tissues. Vitamin D deficiency is widespread, and recommended doses are usually inadequate to maintain healthy levels. We conducted a retrospective observational study to determine whether the recommended doses of vitamin D are adequate to correct deficiency and maintain normal levels in a population seeking health care. We also sought to develop a predictive equation for replacement doses of vitamin D.
Methods. We reviewed the response to vitamin D supplementation in 1327 patients and 3885 episodes of vitamin D replacement and attempted to discern factors affecting the response to vitamin D replacement by conducting multiple regression analyses.
Results. For the whole population, average daily dose resulting in any increase in serum 25-hydroxyvitamin D level was 4707 IU/day; corresponding values for ambulatory and nursing home patients were 4229 and 6103 IU/day, respectively. Significant factors affecting the change in serum concentrations of 25-hydroxyvitamin D, in addition to the dose administered, are (1) starting serum concentration of 25-hydroxyvitamin D, (2) body mass index (BMI), (3) age, and (f) serum albumin concentration. The following equation predicts the dose of vitamin D needed (in international units per day) to affect a given change in serum concentrations of 25-hydroxyvitamin D: Dose = [(8.52 − Desired change in serum 25-hydroxyvitamin D level) + (0.074 × Age) – (0.20 × BMI) + (1.74 × Albumin concentration) – (0.62 × Starting serum 25-hydroxyvitamin D concentration)]/(−0.002). Analysis of the dose responses among 3 racial groups—white, black, and others—did not reveal clinically meaningful differences between the races. The main limitation of the study is its retrospective observational nature; however, that is also its strength in that we assessed the circumstances seen in usual health care setting.
Conclusions. The recommended daily allowance for vitamin D is grossly inadequate for correcting low serum concentrations of 25-hydroxyvitamin D in many adult patients. About 5000 IU vitamin D3/day is usually needed to correct deficiency, and the maintenance dose should be ≥2000 IU/day. The required dose may be calculated from the predictive equations specific for ambulatory and nursing home patients.
Vitamin D dosing calculator ?
Well, you can create your own calculators. I have some examples already written in Synapse
The Role of the Parent Compound Vitamin D with Respect to Metabolism and Function: Why Clinical Dose Intervals Can Affect Clinical Outcomes
.... basically there's storage pool of vitamin D as 25OH present which is tightly bound to vitamin D binding protein
It's only accessible to renal, brain and placenta because they have a special endocytic transport mechanism.
Every other tissue lacks this transport system so does not have access to the stored vitamin D
So, to get benefit for muscle, prostate etc, you need to take Vitamin D daily (and for presumably cancer, immune system)
The American Geriatrics Society is now recommending 4000IU daily from all sources of which 1000IU can be as a supplement
So, you can take 50,000IU once a month for osteomalacia/osteoporosis
but you still need to take 3000IU daily somehow
Hospital Lab report from Canada.
>250 is only "potential" adverse effects.
FWIW, I've never seen anyone over 200.
I have. Reached 250. No ill effects though I did pick up hypercalciuria.
Canadian Vitamin D normal range.
25-HYDROXY-VITAMIN-D Normal range 75-250 nmol/L. Insufficient is 25-74 nmol/L. Deficient is <25 nmol/L
Note that is nmol/L
In ng/ml (American Units) .. The "Canadian" Normal range for 25-HYDROXY-VITAMIN-D (aka Vitamin D) is 30-100 ng/ml, Insufficient 10-30, Deficient < 10 ng/ml.
Note: here is an article about Vitamin D and diabetic neuropathy.
The article says they "corrected for sun exposure". Really ? I'll say that any correcting for sun exposure is likely so flawed it's irrelevant (even without knowing how they did it).
Not sure I'm convinced about the relationship.
But I might suggest it to patients ... based on the usual Vitamin D arguments (it's cheap, might help lots of things, and is very likely safe !).
Note: I found a good calculator to convert American Units of Vitamin D and what the rest of the modern world uses ....
High-dose oral vitamin D3 supplementation in rheumatology patients with severe vitamin D3 deficiency.
von Restorff C1, Bischoff-Ferrari HA, Theiler R.
Recent large trials indicate that adherence associated with a daily regimen of vitamin D is low and limits anti-fracture efficacy with vitamin D supplementation. The aim of this report is to describe changes of 25-hydroxyvitamin D (25(OH)D) serum concentrations achieved with a single oral dose of 300,000 IU vitamin D3.
Over a course of 4 months, we identified 33 elderly with severe vitamin D deficiency (25(OH)D<25 nmol/l) on admission to acute care. Patients were admitted for musculoskeletal pain, bone disease, or gait abnormalities. The mean age was 80.5 years (SD+/-6.1). All patients were treated with a single oral dose of 300,000 IU D3 in combination with 500-1000 mg calcium supplements per day depending on their dietary calcium intake.
Baseline mean 25(OH)D serum concentrations were 15 nmol/l (SD+/-5.5). Mean 25(OH)D serum concentrations increased to 81.4 nmol/l (SD+/-29.7) at 3 months (29 patients) and were still 69.0 nmol/l (SD+/-17.9) at 6 months (26 patients). Mean serum calcium levels were 2.24 mmol/l (SD+/-0.11) at baseline, 2.28 mmol/l (SD+/-0.18) at 3 months, and 2.28 mmol/l (SD+/-0.13) at 6 months. Two patients with mild hypercalcemia (2.69 mmol/l) at 3 months had normal values at 6 months.
Based on our observations, a single oral dose of 300,000 IU vitamin D3 raises mean 25(OH)D serum concentrations to the target mean of above 75 nmol/l at 3 months and a mean level of 69 nmol/l at 6 months. As calcium absorption is enhanced with higher 25(OH)D serum concentrations, calcium supplementation may need downward adjustment with this regimen to avoid mild hypercalcemia.
Effects of one dose of 300,000 IU x 1.
Vitamin D level:
baseline = 15.
3 months = 75
6 months = 69.
I'm not sure how I might get a patient to take 300 tabs of 1,000 IU x1.
Separate names with a comma.