Vitamin D (calciferol)
- 1 Definition
- 2 Reference Area
- 3 Vitamin D sources
- 4 Vitamin D deficiency disease
- 5 Recommended vitamin D intake
- 6 Poisoning of excessive doses
- 7 Pregnancy and vitamin D levels
- 8 Autoimmune diseases, vitamin D and rheumatic disease
- 9 Can you count on the laboratory measurement of vitamin D in the blood?
- 10 Does Vitamin D Prevent Diseases?
- 11 Vitamin D supplement
- 12 Literature
Vitamin D must be administered via diet or through light from the sun. Vitamin D is converted in the kidneys to 1,25 dihydroxyvitamin -D3 which is active ingredient. In blood sample (serum), vitamin D is measured in the form of 25 (OH) vitamin D. Vitamin D deficiency may be unfortunate for the development of rheumatic disease.
25 (OH) vitamin D should be higher than 50 nmol / L.
- An upper limit is uncertain. Many laboratories suggest 100nmol / L as the upper reference area
- Level below 25 nmol / l is considered too lowbut the health impact is seen by some lower values such as 12 nmol / L
- Severe vitamin D deficiency is considered lower than 12,5 nmol / l
Vitamin D sources
- Diet: Fat fish (like herring, mackerel and salmon), butter, margarine and milk with added vitamin D
- Sunlight's ability to prevent rickets (English sick) was detected by the doctor Theobald Palm in 1890. Rocket was one of the most common causes of physical developmental disability at that time
- Summer sun: 5-15min / on face and arms or 4 minutes on whole body is sufficient a couple of times a week. Vitamin D levels are halved during 5 weeks
- Solarium is not recommended due to increased risk of Malignant melanoma (Malignant melanoma) which is 20-40x increased in fair-skinned.
Vitamin D deficiency disease
Vitamin D helps the gut absorb calcium from foods, but also to strengthen the skeleton.
- Vitamin D deficiency in children is seen rickets (English disease) which results in skeletal growth disorders. Similarly, among adults osteomalacia (soft bones) and osteoporosis (osteoporosis).
- Vitamin-D deficiency occurs in chronic renal failure, due to lack of sun exposure (dark skin especially exposed), malnutrition and diseases that reduce intestinal uptake (e.g. chronic bowel inflammation or intestinal manifestations of rheumatic disease).
Some suspect that low vitamin D levels may increase the risk Multiple sclerosis (MS), diabetes, Rheumatoid arthritis (arthritis), SLE, high the blood pressure, Coronary heart disease and cancer. There is research to detect whether vitamin D supplements may seem preventative, but per 2019 such relationships are not proven.
Recommended vitamin D intake
Different denominations can make recommendations difficult to compare. Often IE (international units), other times nmol or micrograms are used. The United States Recommends (Inst of Medicine, IOM) recommends an intake of 600IE / day (16 microgram) for persons <70 years and 800IE / day (20 microgram) for> 70 years.
- In Norway (Food Safety Committee) recommends increasing daily vitamin D intake:
- From 300 to 400IE (from 7,5 microgram to 10 microgram) for adults
- From 400 to 800 IE for elderly over 75 years (from 10 micrograms to 20 micrograms).
- Overweight with BMI > 30 needs twice as much as by normal weight.
- An increased intake of 100IE increases the serum level of 2,5nmol 25 (OH) vitamin-D. About 20 my whole body sunbathing midsummer in Oslo provides increased vitamin D on 15.000IE (reference: Moan, J & Juzieniene, A to Dagens Medisin 11.04.2013).
Poisoning of excessive doses
There should be severe doses before poisoning (intoxication) occurs. Vitamin D intake up to 10 000 IU / day is associated with serum concentrations of 25 (OH) D ≥ 80 nmol / L higher than recommended but without the expected signs of vitamin D toxicity. An upper limit of 4000 IU / day is outlined as safe without the risk of poisoning. However, vitamin-D increases the calcium level in the blood / serum. If pre-existing sickly elevated levels (for example, in hyperparathyroidism) are present, it may cause serious consequences, including heart rhythm disorders. Measurement of ionized calcium in serum (blood) and if necessary also parathyroid hormone (PTH) is recommended.
Pregnancy and vitamin D levels
It is important to correct for low vitamin-D before and during pregnancy because Vitamin D deficiency is associated with increased risk of various types of pregnancy complications.
- It is recommended not to give more than 600IE / day. This is to prevent that some with (undiscovered) elevated calcium levels get too much, which can cause birth defects. Calcigran Forte in full dose (800 / E) may then be to much
- Measurements of calcium and 25 (OH) Vitamin D in pregnancy (preferably at the forefront) may therefore be recommended
- A basic level of at least 50-75 nmol / l of 25 (OH) D concentration is recommended (Endocrine Society, USA and The Institute of Medicine, USA)
Autoimmune diseases, vitamin D and rheumatic disease
Vitamin D has immunoregulatory properties, but its mechanism of action is complicated. Vitamin D increases the differentiation of CD4 + T cells, contributes to antigen and lectin-mediated inhibition of proliferation, reduces IL 2 interferon gamma and GM-CSF secretion increases CD4 + CD25 + Foxp3 regulatory T cell numbers and activation. Vitamin D exposure / treatment reduces IL-12 production from dendritic cells and macrophages. T helper cell effect, as well as TNF-alpha secretion is inhibited. Matrix metalloproteinases inhibit and contribute to reduced tissue damage including arthritis and pathological angiogenesis in autoimmune conditions. Vitamin D deficiency can theoretically, through the immune system, play a role in development and possibly the course of SLE. However, there is no evidence of this. It is also speculated whether vitamin D can prevent infections. However, a study from Tromsø did not find a connection between self-reported respiratory infection and vitamin-D level in adults (reference: Robertsen S et al. 2013).
Can you count on the laboratory measurement of vitamin D in the blood?
In fact, the measurements (25 (OH)-Vitamin D are not accurate:
- Measuring the same samples in one laboratory showed vitamin D deficiency (<50nmol / L) in 43% while another laboratory found similar in just 8%
- If you are in doubt about the need for vitamin D supplements, more tests may be appropriate
- Routine examination of Vitamin D among people without topical symptoms is unlikely to be helpful
Does Vitamin D Prevent Diseases?
Studies have not provided evidence that the supply of vitamin D to populations increases the life expectancy, the occurrence of cardiovascular disease, cancer or diabetes. There is also no effect on the prevention of bone fractures in population studies.
- Sobriety is encouraged to avoid useless intake of D vitamins among people who are not exposed to low levels
Vitamin D and rheumatic disease. Vitamin D supplements may be necessary, especially when you get a little sun.
Vitamin D supplement
- A portion of salmon (150g) contains 24 microgram vitamin D (sufficient daily dose)
- A tablespoon of fish oil ("Tran") contains 15 microgram vitamin D (adequate daily dose)
- Calcigran Forte 1g / 800IE / day contains both calcium and vitamin D which is a topical combination when one wants to keep vitamin D levels high enough over time. Disposable persons reduce the risk of osteoporosis. (Osteoporosis) and corrects low vitamin D values.
- Calcium (500mg) and vitamin D (800IE) are also found in capsules to swallow (Kalcipos Vitamin D)
- At D vitamin level is below 25 nmol / L recommended supplement with Nycoplus D Vitamin (10 MCG) (dietary supplements not listed in the "Common Catalog"): 3 - 5 tablets daily during one month and dose adjustment when control samples show normal values
- At D vitamine level from 25 - 50, Nycoplus D Vitamin is recommended 10 mcg 2-3 tablets daily
- At D white level from 50 - 75; 1 tablet 10 mcg daily
- One should take monthly vitamin D status checks until the samples are normalized and the patient comes to a maintenance dose of 1-2 tablets daily.
- Divisun is a vitamin D alternative (on prescription) where each tablet contains 800IE (20 microgram)
- SR Dahl 2014
- LM Helsingen 2015
- RW Chesney 2012 (How the sunshine vitamin was discovered by Theobald Palm)