Vitamin D conversion

(Sheri Knauer) #1

I was at the pediatrician with my daughter the other day and she asked me how my daughter (12) was getting her vitamin D. I told her she eats cheese and yogurt and goes out in the sun. The ped then said some recent studies have found that people are not converting vitamin D from sun exposure like previously thought so she should drink more milk (she has never been a milk drinker and I didn’t think to ask the ped at the time what studies those were) and it got me thinking. Do you think it’s possible that excess linoleic acid in the diet is interfering with vitamin D conversion from the sun? The first time I heard Tucker Goodrich on a podcast about 2 years ago, he had mentioned that those who ate excess linoleic acid tended to burn easily because of a reaction between sun exposure and the excess linoleic acid in the tissues oxidizing (or something like that). Could excess LA in the tissues also hinder the conversion of vitamin D to a usable form? So even if we do advocate for someone who has been eating a lot of LA and has an excess amount in their tissues to get more sun exposure to increase vitamin D levels, will it really do any good if at the same time they do not eliminate seed oils from their diet? Just curious on others thoughts and if anyone knows of any studies backing my thoughts on it.

(Bacon by any other name would taste just as great.) #2

It might not be excess linoleic acid, so much as a lack of saturated fat, but I wouldn’t dismiss Mr. Goodrich’s points, either. Vegetable oils are so high in polyunsaturated fatty acids that they should be avoided. Vitamin D is manufactured in the body from cholesterol (and so are many important hormones), so a good source of saturated fat in the diet is a good idea.

If you live in the U.S., the reason your doctor is telling your daughter to drink more milk is that commercial milk has been fortified with vitamin D for about a century, now.

I personally try to eat as little vegetable oil as possible (it’s not completely under my control, because I don’t do all the cooking in the household). I find that, after a couple of years on a ketogenic diet, I can now be out in the sun mowing the lawn for four hours with no sunburn, whereas as a carb-burner I found that I became so sensitive to the sun over the years that SPF greater than 80 was not enough to keep me from burning if I stayed out in the sun longer than 30 minutes. (When I was a lot younger, SPF 20 was enough to let me be out in the sun for many hours.)

(Michael - When reality fails to meet expectations, the problem is not reality.) #3

There are 22 citations with this article.

[19] demonstrated a decrease in sickness with supplementation. The supplementation was Vigantol – vitamin D3 dissolved in triglyceride. Multiple studies from 1930s demonstrated significant improvement of respiratory immunity from taking cod liver oil [5], which contained not only vitamin D, but also Omega-3 fatty acid, and vitamin A. The effect of combined vitamin D / Omega-3 supplementation is a promising avenue for research. A word of caution: some sources say that modern techniques of cod liver and other fish oil preparation remove most vitamin D.

[21] and [22] reported an inverse correlation between sunlight UV and COVID-19 mortality,. This might be due of the anti-inflammatory effect of vitamin D and is out of the scope of this paper.


Exposure to UVB in sunlight or artificial UVB sources, in proper amounts and adjusted by skin phototype (dark skin might need 5-6 times more exposure than light skin), is necessary for maintaining normal innate immunity. Vitamin D supplements do not produce the same benefits or immunity as UVB exposure. UVB stimulates production of cathelicidin and other AMPs in the skin and/or certain blood cells travelling through skin. These AMPs are carried by the blood to the respiratory tract surfaces and enhance innate respiratory immunity.


I was low in Vit D and I just went with D3 supplements. It is harder for the over 60 crowd, like me to utilize the sunshine source from what I have been reading.

I can not abide milk and have never drank it (cream is something else entirely. Dr.s recommend it as it is fortified so not drinking it and just supplementing should be just fine for your child.

(Jane) #5

Same here. I have fair skin that used to burn after an hour in the sun with high SPF sunscreen on. I never use sunscreen anymore and don’t burn now. I wear a straw cowboy hat when I am mowing for 2-1/2 hours but mostly for comfort, not to prevent sunburn.

(Bob M) #6

I still get burnt every year, low carb almost 7 years. I think that’s because I go from zero sun to a ton of sun. If I had a normal transition, with even 15-30 minutes of sun, it might be better.