Maintaining Vitamin D Levels in Autism

This post is part 2 of the original post entitled Vitamin D and Autism Spectrum Disorders.

Given that vitamin D is required by the human body whether or not autism is present, it makes sense to ensure that your child’s vitamin D requirement is being met. To know what child’s vitamin D level is, ask your doctor. A simple blood test can be used to determine whether or not they are deficient.

The body gets vitamin D from 3 different sources: sunlight, food and dietary supplements. The two major forms of vitamin D are vitamin D2 and vitamin D3. Vitamin D2, also known as ergocalciferol, is largely human-made and added to foods, whereas vitamin D3 (cholecalciferol) is synthesized in the skin from sunlight and is also consumed via the intake of animal-based foods. Both forms are also commercially synthesized and found in dietary supplements or fortified foods.

Vitamin D and Autism

Vitamin D3 is synthesized in human skin following exposure to ultraviolet B (UVB) radiation . In our modern world, we spend very little time outdoors compared to what was normal even twenty years ago.   It’s worth noting that while toxic levels of vitamin D do not occur from prolonged sun exposure, too much sun can lead to premature skin aging and skin cancer. That explains why parents receive repeated warnings about protecting children from sun exposure.  But there needs to be a balance.

How much sun exposure should a child get for adequate vitamin D formation? Well that will depend on which part of the world you live in as well as other lifestyle factors. The amount of UVB radiation available for absorption depends on the angle at which the sun’s rays strike the earth, the presence of clouds and buildings, ozone and aerosol pollution, altitude and reflective surfaces such as snow.

Because of the effect of the sun’s angle, one group of researchers concluded that even in completely clear skies, synthesis of vitamin D in the skin is impossible during at least part of the year at any latitude above 34 degrees. On a United States map, if you draw a line between Los Angeles, California and Columbia, South Carolina – any cities above that line are at a latitude north of 34 degrees. The same is true for those living below or south of 34 degrees latitude in the southern hemisphere (draw a line from Buenos Aires, Argentina to Cape Town, South Africa to Sydney, Australia).

In addition to environmental factors, skin pigmentation, lifestyle habits as well as age can also affect one’s ability to obtain vitamin D from the sun. People with dark-colored skin synthesize less vitamin D on exposure to sunlight than those with light-colored skin. The risk of vitamin D deficiency is particularly high in dark-skinned people who live far from the equator as well as in people who dress conservatively, either for religious reasons or weather reasons, because less skin is exposed.

Keep in mind that the simple use of sunscreen with SPF 8 reduces UVB penetration by 98 percent and essentially abolishes the production of vitamin D. We live in a culture where “if a little is good, then a lot must be better.” Sunscreens use to have a sun protection factor (SPF) of 15 at the high end. Nowadays, it’s not uncommon to find SPF in the range of 70+. This virtually eliminates all ultraviolet (UV) ray absorption from the sun. Since our body’s main source of vitamin D is dependent on the reaction of our skin to the sun’s UV-B rays, I propose that use of a high SPF sunscreen may not be such a good thing.

How to Vitamin D from Sunlight
Short daily periods of sun exposure without sunscreen during the warmer months (May to September in the Northern Hemisphere and November to March in the Southern Hemisphere) are enough for most people to make enough vitamin D. Evidence suggests that the most effective time of day for vitamin D production is between 11am and 3pm.

A short period in the sun means a matter of minutes – about 10 to 15 minutes for most people – and is less than the time it takes skin to turn pink. The larger the area of skin that is exposed to sunlight, the more chance there is of making enough vitamin D before skin starts to burn. People with darker skin will need to spend longer in the sun to produce a comparable amount of vitamin D.

Caution should be taken in prolonged sun exposure to prevent sunburn. After “soaking in” vitamin D for the recommended amount of time, be sure to apply sunscreen to prevent sunburn as well as risk of skin cancer.

Individuals who avoid the sun, have limited sun exposure or live in the “vitamin D block out area” of the world need to include good food sources of vitamin D in their diet or take a supplement.

Food Sources of Vitamin D
Because the body cannot always get enough vitamin D from the sun, it can also be ingested. Fatty ocean fish like salmon, halibut and tuna are a good source of vitamin D and omega-3 fatty acids. Both are important for brain health.  Some foods, like non-dairy milk and cereal, are often enriched with vitamin D. Other Vitamin D-rich foods include egg yolks, and organ meats like liver.

Whenever possible choose organic eggs that come from free-range chickens. Free-range is a term that denotes a type of farming where the animals can roam freely for food, rather than being confined in an enclosure that prevents exposure to sunlight. If chickens are being raised in an indoor housing system, as are most chickens in the US these days, they are not seeing sunlight at all. If they aren’t getting vitamin D from the sun, the eggs they produce will definitely not be a good source of vitamin D.

Vitamin D Supplements
Vitamin D3 (cholecalciferol) is the form of vitamin D that the body makes from sunlight, and experts agree that supplements containing the D3 form are better absorbed and more effectively utilized by the body.

Because vitamin D is a fat soluble vitamin, the body can store it.  Theoretically, this means that levels of Vitamin D could reach a toxicity point.   For this reason, it is very important to approach supplementation wisely and with your doctor’s knowledge and recommendations.

The recommended daily allowance of vitamin D for children ages 1-18 is 600mg per day. Children with chronic illnesses such as autism, diabetes, and/or frequent infections should be supplemented with higher doses of sunshine or vitamin D3. One source suggests that if vitamin D is determined to be a risk factor for autism, then autistic children should have their vitamin D levels raised to above 30-40 ng/ml, which could take 1000-2000 IU/d of  vitamin D3, or more depending on such factors as genetics, weight and amount of time spent in the sun. Consult your doctor to determine which dose is right for your child.

Have you used Vitamin D supplements with your child? What has been your experience? Please comment below.


If you have enjoyed this article, please share it on your social media networks and forums. Parents of special needs kids are always looking for valuable info. Thanks!


This post is an excerpt from the ebook:E.A.T. An Italian Mother’s Guide to Going Casein-free in Autism Spectrum Disorders now available on Amazon. 

Vitamin D Supplements

I love these because they are free of: Yeast, Wheat, Milk, Egg, Soy, Salt, Tree Nuts, Peanuts, Shellfish, Gluten, Artificial Colors and Flavors, Salicylates and Preservatives and they are GMO Free!


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National Research Council. Dietary Reference Intakes for Calcium and Vitamin D . Washington, DC: The National Academies Press, 2011.

From Seafood to Sunshine: A New Understanding of Vitamin D Safety

Webb, A. R. Kline, L. Holick, M. F. “Influence of season and latitude on the cutaneous synthesis of vitamin D3: exposure to winter sunlight in Boston and Edmonton will not promote vitamin D3 synthesis in human skin,” J Clin Endocrinol Metab., 1988; 67(2): 373-8

Rahmaniyan. Bell. “Effects of Race, Geography, Body Habitus, Diet, and Exercise on Vitamin D Metabolism.” In Feldman, D. Pike, J.W. Glorieux, F.H. eds., Vitamin D: Second Edition, Burlington: Elsevier Academic Press, 2005; 789-801. (Review)

Antico A, Tampoia M, Tozzoli R, Bizzaro N: Can supplementation with vitamin D reduce the risk or modify the course of autoimmune diseases? A systematic review of the literature. Autoimmun Rev 2012


  1. says

    Probably one of the best little write ups I have read on calcium sources so far. Very happy that you mentioned about Vitamin D3 in particular which plays a great role in helping our body absorb the calcium we consume. I hope next time you discuss some plant based sources such as beans, spinach etc. In my opinion, plant based food sources for any nutrient is way better than animal sources.

    • sharingmom says

      Yes! Thanks for your comment. I have that info coming up in a future post. Please make sure you are subscribed to this blog so you can receive it via email.

  2. says

    Dear Sharing Mom,
    I think my comment disappeared so will try to recreate it…I just wanted to thank you for your really helpful and clear information on Vitamin D. We live up North AND are a vegetarian family so, like @Plant Based Bobby, would love to hear more thoughts on plant-food sources. Thanks and Love, FSM

    • sharingmom says

      Yes! Thanks for your comment. I have that info coming up in a future post. Please make sure you are subscribed to this blog so you can receive it via email.


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