Overview Rare Allergic reaction to vitamin D
It appears that about1 person in 300 people has an allergic-type reaction to vitamin D within days.
(Have no specific reference - it is just an impression from reading 12,000+ articles on vitamin D)
The allergic reaction may include itchy skin, hives, and intestinal upset.
The reaction is real, and the cause varies
Possible reasons and solutions
- The reaction is typically due to a lack of Magnesium - Mg is required by Vitamin D
- Solution take Magnesium supplement for a week and try again
- It might be similar to reaction to the sun - probably previously known
- Red-heads and others - try a smaller dose initially
- See also Photosensitivity (sun allergy) and vitamin D
- Does size too big - at least initially
- Perhaps we need to start with a smaller dose, say 1000 IU, and get used to vitamin D for a week or so
- Might be a reaction to Vitamin D2 Vets determined that D2 should not be given to any mammals
- Solution - use Vitamin D3, not D2
- The reaction by the gut
- Try a sublingual form
- Try a gut friendly or topical form
- Try a vitamin D patch on the skin
- Try a processed form (calcitriol, etc.) - click on the chart below for details
- Try an injection (lasts longer) - click on the chart below for details
- Reaction to the fillers (oil, etc.), additives, coloring, the gelatin capsule
- Try a pure and clean form such as by Bio-Tech Pharmacal
- Rare reaction to Wool/Lanolin
- Try a plant form of D3
- Extremely rare reaction to Vitamin D3 in regular/processed forms
- Use sun or UV bulb to generate Vitamin D in your skin - click on the chart below for details
Interaction of vitamin D with a prescription drug is very rare to have a drug reaction
Rare mutation of CYP24A1 gene results in Vitamin D accumulating
Many ways to increase Vitamin D

See also VitaminDWiki
People allergic to Lanolin should not be allergic to vegan Vitamin D
Woman with rare allergy to vitamin D was desensitized in a single day – Dec 2016
Side Effects and Warning for vitamin D
- Excessive thirst, Metal taste in the mouth, Poor appetite, Weight loss, Bone pain, Tiredness, Sore eyes, Itchy skin, Vomiting, Diarrhea, Constipation, A frequent need to urinate, Muscle problems
All items in category Interactions items (virtually all interactions = Drug reduces the vitamin D effectivity, no reaction
Vitamin D interactions with drugs – Oct 2011 Abstract says which drugs, but no amount of interaction
Response and adverse effects of 20,000 and 30,000 IU Vitamin D weekly - Feb 2015
On-line survey of drug uses and side effects – including vitamin D
- Which contains the following table:
Note This is a % of the small % who had any reaction to vitamin D

Perspective: 3X more likely to be allergic to Aspirin than to Vitamin D
Repeat the above information - for cut and paste as of Jan 2016
About 1 person in 300 gets a reaction to vitamin D
That rare reaction is due to the following 9 reasons
Lack of Magnesium
Reaction to the sun (if already known)
Does size too big initially
Reaction to Vitamin D2, not D3
The reaction by the gut
Reaction to additives, fillers, colors, etc.
Rare reaction to Wool
Extremely rare reaction to Vitamin D in any form
Extremely rare Interaction with a prescription drug
short URL = http://is.gd/allergictod
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