Well this is an interesting subject. I think the daily allowance is 400IU but it really really depends on your current Vitamin D levels. You can get the test done by the doctor easily and if it is low you can take up to 3,000-4,000IU a day if you are low. It doesn't matter what time of day you take it, what form it is, you can even take a whole week dosage at one time as it is stored within the body over a period of 3 months. Vitmain D is a hormone in which slows down the multiplication of cells having less chance of defects ie. Cancer, diabetes, ulcers etc. You can get enough Vitmin D from the sun if you spend enough time in the sun. If you are darkere skin or tan easily then you have a bigger resitance to obsorbing Vitamin D from the sun. There are a lot of factors so if you can get your levels checked.
When you purchase vitamin D, make sure you purchase "Vitamin D3".
I agree with the above posts.....my doc had me on 4,000IU when mine went low,,,I am on chemo right now and I am afraid the D might interfere with the meds so I bought a tanning bed for my home and this way I just have to sit under the light every other day and get 20,000IU real quick. Of course with taking the meds, ya have to be careful not to burn as your skin is more sensitive and I am not advising anyone on meds to do this - I am doing it because as soon as the summer sun went away, my vitamin D level started to immediately drop.....BTW the most accurate Vitamin D test is at Lab Corp - Dia Orsini or something like that it is called - I have to run out otherwise I would double check the name,,,but if you get the test there, you don't have to know the "actual name",- that IS the test they will use(doc will just check off vit d test).
sitting in the sunlight for 15 min daily is all that is required.
Have your Vitamin D checked. I also heard that tanning beds do not give you the Vitamin D so not sure about a sunlamp. Coral Calcium has Vitamin D3 so it's a good source as well as most fish, especially salmon. Vitamin D deficiencies can cause serious problems. Mine was just tested at 40 and it was 11.8, well below normal and it took months of arthritis pains, gout, paresthesias, four doctors, etc. for one doctor to say, "Haven't they ever tested your Vitamin D?" This is when you want to write a letter to the previous doctors to let them know what they missed so another patient doesn't have to go through this. At my levels children can get rickets and elderly people have fractures but it took 6 months for me to find a qualified doctor. It is also suspected to make your heart attack risk 50% higher at low levels and has been seen in Parkinson's and Alzheimer's, so it's a pretty important Vitamin. You can get Vitamin D toxicity so it is important to have it checked and take the proper amount.
Vitamin D3, more and more studies indicate this nutrient has amazing benefits for promoting a healthy immune system and good cellular health. The optimal dosage is 2,000 – 4,000 IU per day, far higher than most multi-vitamins containing only 400 IU; it appears 800 IU per day or under seems to have little benefit for immune function. Carlson recently launched 2,000 IU vitamin D3 drops which are great for kids and adults who cannot swallow a small softgel or capsule. There is a 2008 vitamin D3 human study2 in the scientific journal called Virology Journal that I strongly recommend you read and share with your family, friends and coworkers.
Since I post this in July 2008.... I went to see my Orthomolecular Specialist and he said you can never overdose on Vit D ...ever...and it's not toxic in highier doses. I have been taking about 8.000 IU which is only 200 mcg a day and never had any adverse reactions. My 25-Hydroxy Vit D test in September 2008 showed my level at 110 which is a good thing. I am continuing with large dose and will up my dose to 10.000 ......250 mcg soon.
I just hope all cancer patients took Vit D in large amounts...the best is a drop form.Every drop is 1000 IU ( 25 mcg) of pure Vit D 3.
I buy mine in Natural food store....I checked Drug Stores and they too have it in drops but they also contain color and flavour . To me it's not pure anymore.