When the Sun Goes Away, So Does Your Vitamin D

Ali Segersten Jan 03, 2009 14 comments

We have had a lot of snow recently! With all of the cold weather and cloud cover, sunshine is not able to reach our skin to allow for the formation of vitamin D. In fact, anywhere North of an imaginary line (the 35th Parallel) running through Bakersfield, California, Oklahoma City, Oklahoma, and Raleigh, North Carolina, the sun's rays are not strong enough for vitamin D formation in the Winter. The farther away from the equator you live, the longer the season of vitamin D shortage.

Health experts recognized an epidemic of vitamin D deficiencies at the turn of the century and years later our food was fortified as a result. However, recent research is now clear in stating that, even with fortified foods, in the absence of adequate sun exposure , it is virtually impossible to meet your daily needs of vitamin D from foods.

After just returning from a conference on vitamin D with some of the world experts on the subject, it is clear that vitamin D might be the most important hormone in the human body. Whether it is helping with bones, blood pressure and heart disease, cancer, diabetes, or the prevention of the flu, vitamin D plays a role in maintaining normal function in every cell of our bodies.

So what do we do in the dark winter months? Either take a trip to Hawaii, or use supplements. If Hawaii is not an option, experts are saying that adult humans require about 3,500 to 3,800IU of vitamin D per day, and infants and children need close to 1000 IU per day per 25 pounds of body weight. Pregnant women need around 6000 IU's per day. If serum levels of 25-hydroxy vitamin D are low in adults, doses of 5000IU or more could be called for.

An inexpensive finger prick bloodspot test to look at 25-hydroxy vitamin D levels can be obtained through participation in the Vitamin D Action Network at Grass Roots Health. Current recommendations for 25-hydroxy vitamin D levels are between 45-80 ng/mL, with higher levels possibly needed in the prevention and treatment in various diseases.


We give each of our children 1000 IU's of Vitamin D daily. The girls just swallow the tiny capsules with water. With the babies we break open the capsule and mix it with a small amount of applesauce and spoon feed it to them. Ali and I each take 5000 IU's daily during the winter months; less in the fall and spring, and even less in the summer if we get adequate sun exposure. We use the Thorne brand of vitamin D3 because it is one of the only brands available that uses raw materials that are free of all preservatives (like BHT, BHA, sodium benzoate), flowing agents (like magnesium stearate or ascorbyl palmitate), potentially harmful fillers (like lactose), gluten, dairy, and all other common allergens. What you see on their label is all you get. Please contact your local health care provider for availability. Please note that this brand is not sold in stores and is only available through a health care provider.

If you are an undiagnosed celiac or recovering celiac then you will not be able to properly absorb supplemental vitamin D. This is because gluten damages the small intestine where fat, and fat soluble nutrients, are absorbed. It is very important to test for celiac disease or gluten sensitivity if your vitamin D levels do not rise after supplementation.

Here is our recipe for an immune-boosting drink. Be sure to drink this after you have eaten some fat (avocado, olive oil, fish) to help absorb the D. Add extra Vitamin D if you are feeling a bit under the weather!

Super Immunity Cocktail

Serves 1 adult or 2 children

  • the juice of 2 Valencia oranges
  • two 1000 IU capsules vitamin D
  • one 200 mcg capsule selenium picolinate
  1. Place all ingredients into a glass and whisk together using a fork.
  2. Pour into shot glasses and serve immediately!

About the Author

Ali Segersten

Alissa Segersten holds a Bachelor's of Science in Nutrition from Bastyr University and a Master’s of Science in Human Nutrition and Functional Medicine from the University of Western States. She is a Functional Nutritionist, the mother of five children, a whole foods cooking instructor, professional recipe developer, and cookbook author. She is passionate about helping others find a diet that will truly nourish them. Alissa is the author of two very popular gluten-free, whole foods cookbooks and guidebooks: The Whole Life Nutrition Cookbook and Nourishing Meals. She is also the co-author of The Elimination Diet book. Alissa is the founder and owner of Nourishing Meals®.

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Hi Ali and Tom,

Great write-up and learned a lot!Curious what brand of Selenium you use for your family.

Thank you so much!


Hi :)
I'm in the first week of the Elimination Diet and just realized I may not be getting a sufficient ammount of vitamin D. While it is summer here, I still work indoors (with no windows) for at least 40 hours a week. I am also gluten intolerant (undiagnosed). How do you recommend I get the right amount of vitamin D while on this diet? Thank you for your help!


I have been told by several people that you can not over dose on vitamin D. Not sure if this is true - but I would imagine at the very least it HARD to get to much vitamin D.
Also - my mom was told by a nurse practitioner here in Bellingham that the angle of the suns rays in this part of the world do not let us get enough natural vitamin D... even in the middle of summer!
My roommate was advised by a Naturopath in Bellingham to take 100,000 IUs of vitamin D every day while fighting an eye infection.
I take 16,000-20,000 IUs every day and I have finally stopped getting that sleepy feeling in the afternoons that I have had for years!

Vitamin D is critical for anyone with a shot immune system, including those with allergies and autoimmune disorders. My son has both allergies and autism, and his allergist told him to take 4000 IU of vitamin D daily. It was after we started doing this that all his boils went away, and he was no longer battling staph infections all the time.
Vitamin D is no joke. I would take it weekly, if you are so worried about getting way too much.

Thank you soooo much for that link. It was very entertaining to read. I have read 497 scientific articles on this subject, and have heard some of the most prestigious vitamin D researchers in the world lecture on numerous aspects of health. I am completely baffled as to how the group of people that are behind this information ever came to the conclusions they did.
I am reading every page of it now and will get back to you.

It appears that vitamin D is absorbed primarily in the areas in the intestines that are often harmed in celiac disease. However, these same areas are responsible for the absorption of many other nutrients.
I have not seen much data or clinical evidence that vitamin D deficiency will directly effect sleep. I have clients in my clinic benefit from other nutrients like tryptophan or 5-HTP, magnesium, and a form of folic acid called 5-MTHF. If you go to www.pubmed.com (the national library of medicine site), you can type in "digestive and nutritional considerations in celiac disease" and an article I wrote on this subject will explain this process of lack of absorption. If you would like a link to a webinar I gave on this, please e-mail me at tom@wholelifenutrition.net. I would be very happy if some of this information helps your boyfriend get a good nights sleep!

Ali & Tom - There was a recent article (below) in the NYT claiming the need for vitamin D is overblown, and taking supplements is dangerous (!!). Any thoughts here? My cynical mind thinks this is an attempt by the pharmaceuticals to keep us from easy ways to stay healthy. The article emphasizes bone health over other (I would say more critical) measures like cancer risks. I'm going to keep taking my supplements, personally, but it's really confusing sometimes, and I don't trust the media not to emphasize what they want for their own gains...


Hi Ali and Tom,

You mention that if a person has celiac, then he/she will have difficulty absorbing supplemental vitamin D. What should that person do then?

My boyfriend has celiac, and he is on vitamin D supplements after having tests done with his doctor. He is having a terribly time sleeping, and I'm wondering if this is connected to him not being able to properly absorb the vitamin D.

What do you think?

Thanks so much for your advice and have a wonderful Thanksgiving! I'm making your pumpkin cheesecake to share with my boyfriend's family. :)

~ Laura

I realize this is a year late, but you can now buy the Thorne Vitamin D on Amazon without needing a healthcare provider to do it for you. It's surprisingly cheap, too - only $8 or so for 90.

This was helpful. Thanks for taking the time to write it up. I have liquid drops that are 250 IU that I give my son, but will increase the amounts. I was told for babies not to use more than 250, clearly that's not what you do in the northwest.


nevins - Thanks for the cancer and D information.

Shirley - Thanks for the additional info on vit. D!

Kboigirl - Glad we provided you with some useful info for your upcoming time in grad school.

Thanks for your comments.

I'm currently researching the effect supplemental vit D has on the bone density in women 65 and older. I'm an undergrad in nutrition and am applying for a master's program to begin in the fall. Vitamin D and senior nutrition is my focus and I appreciate all vitamin D info I can get!

Outstanding article, Ali! What a great conference that must have been! I just took my daily dose of Vit D (varies from 4000 to 6000 IU) along with my other supplements. Vit D is needed by so many. And, I truly believe that once you've had celic/gluten intolerance, you will need supplementation on some vitamins/minerals forever. And, high quality supplementation, at that. I've reached satisfactory levels in several areas before, but over time, without supplementation, I slide back to below average and feel poorly--even eating very well.

nevins--Not only does vitamin D lower an individual's cancer risk, it also lowers the risk of recurrence (undertandably) if one has had cancer. Yet, I don't know of any local doctors who tell their patients about Vit D. I've had numerous relatives who have had cancer. When I tell them about the value of Vit D (and other supplements), they dismiss it because their doctor has not mentioned it. Then there are the annoying news reports from time to time on studies that indicate that people who take supplements are no better off than those who don't and that folks are wasting their money. I know differently. (Who does those studies? And, how are they conducted?)


Taking 1000 international units of the vitamin D daily could lower an individual's cancer risk by 50-per cent, they said. Cardio Cocktail contains 5000 mg of vitamin D3 per ounce.

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