Vitamin D Craze – Too Much of a Good Thing is Still Toxic

I’m seeing posts everywhere about mega doses of vitamin D >> one “expert” said they take 50,000 I.U. a day!!! Wow. Vitamin D is definitely a very important one and due to chem. trails or lack of sunlight/geography, most people are most likely deficient and that certainly does put them at high risk for many serious health issues.

But this is not a water-soluble vitamin >> meaning your body doesn’t just excrete what it doesn’t need like it would with B vitamins. Vitamin D needs to be processed by your kidneys and really excessive amounts can be very taxing.

Safe amounts > this is quite subjective even among doctors which prevents me from making any recommendations on dosages. I personally supplement with 1000 I.U./day in winter months 4-5 days/week and I try to absorb direct sunlight at least 3-4 times a week in the summertime with no sunscreen (sunscreen blocks the absorption of vitamin D up to 95%); and based on my research, I wouldn’t suggest going over 3000 I.U.s.

Vitamin D from Sunlight

Something to consider: when you absorb D through sunlight, there’s an auto “shut off valve” built in to your brilliant body where it stops converting at 30,000 and simply stores the vitamin for later use. However when you take it in supplement form, there is no shut off valve, your kidneys just keep processing – and large overdoses can be harmful. Synthetic forms of all nutrients could never compare to natural forms whether it be via sunlight or food.

[box type=”important”]Editor’s note:  Recommendations for vitamin D intake were recently modestly increased.  [follow the link][/box]


General Vitamin Information:

Water soluble means your body can easily excrete what it doesn’t need through your urine and sweat, so you don’t need to worry about taking too much (within reason of course, 40,000mg of anything is harmful). Fat soluble means your body stores excess amounts in fats through your bloodstream; really excessive amounts can become toxic, but it takes very high amounts to get there. It is always best to consult with a qualified health care provider.

Water Soluble Vs. Fat Soluble Vitamins:

  • WATER SOLUBLE: all B vitamins, including folic acid, and vitamin C
  • FAT SOLUBLE: vitamins A, D, E, K

If you do consume too much in fat soluble, before it gets to any toxic or dangerous level, you will feel yourself getting a little tired and lethargic – this is your body telling you there is too much for it to process. The trick is to go ahead with water-soluble vitamins, and then with the fat soluble ones, start with RDA’s and then one by one, increase dosages in small increments and see how you feel.

This will take several months to accomplish because you need to isolate each fat soluble vitamin for 2-3 weeks as you try different levels. You must do this one at a time so that you know exactly how you are reacting to each particular vitamin. If you feel that heaviness/tiredness, immediately cut back dosages.

Jaqui Karr

Gluten and Nutrition Expert, Bestselling Author, Jaqui Karr is the authority on gluten - Visit Jaqui's website now for information about how gluten is destroying your health

2 thoughts on “Vitamin D Craze – Too Much of a Good Thing is Still Toxic

  • March 30, 2011 at 5:50 pm

    Yes anything in excess can lead to toxicity and should be avoided. Regarding vitamin D, a balanced diet and regular exposure to sun can give you sufficient amont and there is no need to take supplements.

  • March 30, 2011 at 10:36 am

    I take 10,000 IU per day in Winter and then later inthe year, I gradually reduce the dose, so that the net intake from supplements and sunlight is about 10,000 IU per day.

    There is no risk from overdosing if you get less than 40,000 IU per day. A test with volunteers who took 20,000 IU per day for some months showed no adverse health effects. The known cases of vitamin D overdose all involve people taking more than 100,000 IU per day for quite a few weeks.

    The calcidiol concentration that leads to hypercalemia is not well known. In the US you are considered to be at risk when your level is at 500 nmol/l, but this is just an artificial limit. Tests with rats have shown that even at 1000 nmol/l you don’t see any evidence of hypercalcemia.

    Note that people who take more than 100,000 IU per day for some weeks can get hypercalemia while their calcidiol levels are just a few hundred nmol/l, but this is because the liver is unable to convert Vit D to calcidiol at the rate they are taking it and then the vit D itself accumulates in the body and that then contributes to hypercalcemia.

    Of course, it’s best to stick to levels around 200 nmol/l ( = 80 ng/ml), which is what you would typically have if you take 10,000 IU per day.


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