Why You Need Vitamin D

Are You at Risk for Vitamin D Deficiency?

by Christiane Northrup, M.D.

Preventative Medicine

Vitamin D is necessary for the health of every cell in your body. Yet, Vitamin D deficiency has reached epidemic proportions. Overall, Vitamin D influences more than 200 genes, each of which has the propensity to become impaired without adequate Vitamin D. According to a number of studies, Vitamin D deficiency can result in many diseases and conditions, including obesity, diabetes, hypertension, depression, rheumatoid arthritis, fibromyalgia, chronic fatigue syndrome, osteoporosis, Alzheimer’s disease, and cancers of the breast, prostate, and colon.

Yet, maintaining an optimal level of Vitamin D can improve your immune system function and prevent many diseases, including colds and flu, cancer, and “autoimmune” diseases.  Plus, an optimal level of Vitamin D can improve your mood, regulate insulin, support heart and lung function, protect your brain from toxic chemicals, and may help reduce pain in people with chronic pain conditions.

Know the Risk Factors for Vitamin D Deficiency?

The average Vitamin D level for all women in the US is 29 ng/ml – well below the recommended 40 ng/ml. For African Americans, the average is even lower – 21 ng/ml. Typically, people who are Vitamin D deficient do not know it because symptoms are subtle and often attributed to other conditions. The problem is, some of the symptoms of Vitamin D deficiency can be serious. They include getting sick frequently, experiencing fatigue, chronic fatigue syndrome, bone pain, muscle pain, back pain, fibromyalgia, hair loss, depression, and poor wound healing. If you suffer from any of these symptoms, I recommend that you test your Vitamin D levels.

But, many people who don’t have symptoms are at risk for Vitamin D deficiency. If you live in a climate where you do not get enough sunshine (such as above the 35th parallel), your stores of Vitamin D most likely will be low, at least from November through March. Also, if you have dark skin, you are more likely to be deficient in Vitamin D because melanin reduces your skin’s ability to synthesize Vitamin D from sunlight.

Other individuals who are at greater risk for Vitamin D deficiency include women who cover themselves from head to toe, such as women who wear burqas or niqabs for religious reasons. Also, people who use SPF 30 or higher are at greater risk because sunscreen reduces your body’s ability to synthesize Vitamin D by 95%! Plus, people who work the night shift (and sleep during the day) and people who are homebound are at greater risk of Vitamin D deficiency.

Office workers and people who live in highly polluted areas often have lower Vitamin D levels. So do vegetarians and vegans. Finally, infants who are solely breastfed can develop low Vitamin D levels and should receive 400 IU per day of an oral vitamin D supplement. (You can get drops made specifically for babies.)

Vitamin D and Breast Cancer Prevention

There are many studies that show the connection between Vitamin D and breast cancer prevention. Reduction in risk can range from 55% to as high as 80%, depending on Vitamin D levels. And, it appears the higher your serum Vitamin D the better in terms of preventing cancer.

In addition, much research shows that Vitamin D is extremely important for regulating cell growth. This is very exciting news because not only do adequate Vitamin D levels in women appear to reduce the risk of breast cancer up to 80%, some studies suggest that Vitamin D may reduce the progression of cancer by slowing the growth of blood vessels within the cancer cells, thus causing cancer cell death and reducing the chance of cancer spreading (known as metastasis).

Even more exciting is the fact that Vitamin D is associated with better survival rates among breast cancer patients. A 2014 statistical analysis performed by researchers at the University of California San Diego School of Medicine showed that Vitamin D receptors are not lost until a tumor is very advanced. So, as long as Vitamin D receptors are present, tumor growth can be prevented when Vitamin D levels are adequate.

If you are concerned about your breast health, or you have breast cancer, I recommend getting your Vitamin D level tested and taking a high-quality Vitamin D supplement to get your Vitamin D level to around 60 ng/ml.

How to Test Your Vitamin D Levels

I recommend that everyone test their Vitamin D levels. It’s good to do this when you are feeling well so you have a baseline. If you are having health problems, I definitely want you to get your Vitamin D tested, especially if your symptoms are vague, or if you suffer from a serious condition and are not improving with standard treatments.

Testing is easy and you can do it from home with a home test kit. I like the ones from Grass Roots Health. If you are healthy and looking for your baseline measurement, start with the basic Vitamin D test kit. You can also get one of the more comprehensive kits that allow you to test your Omega 3 index, C-Reactive Protein (CRP), and A1c along with your Vitamin D. You can also do a complete inflammation panel, which is good for people with chronic conditions.

Vitamin D tests are serum tests. This means that you will need to prick your finger. If that bothers you, then I suggest you ask your health care provider to perform a blood test to check your Vitamin D levels. You should specifically ask to have a 25(OH)D test performed, also called a 25-hydroxy Vitamin D. Be sure to get your actual number. Don’t settle for hearing that your Vitamin D is “a little low” or that “you’re okay.”

Ideally, your Vitamin D level should be at least 40 ng/ml – somewhere between 40-60 ng/ml is optimal. Higher levels are also fine up to approximately 100 ng/ml. If you are below 40 ng/ml, I suggest taking Vitamin D supplements until you are in the ideal range. You can use the calculator on Grass Roots Health to determine the amount of Vitamin D you need take to reach your goal of 40-60ng/ml.

Other Ways to Increase Your Vitamin D Levels Naturally

If you are deficient in Vitamin D, the best way to increase your serum levels is to take a high- quality supplement. However, there are two more ways you can increase your Vitamin D levels naturally.

The first way to increase your Vitamin D level is to spend more time outside in the sun. In order for your skin to synthesize Vitamin D from the sun, you need to expose your skin directly to sunlight with no clothing barrier and no sunscreen. Soak in the sun for 5-10 minutes every day or until your skin turns slightly pink. If you have darker skin, you may need to stay outside a bit longer.  I don’t recommend doing this when the sun is hottest, but around 10:00 am is usually a good time.

If you live in a climate where you cannot get adequate sun exposure during any part of the year, invest in a broad-spectrum light box. These produce the light you need – but without the UV rays – and are effective in helping your body synthesize Vitamin D. Plus, light therapy can reduce symptoms of Seasonal Affective Disorder (SAD), help you get a better night’s sleep, and reduce cravings for sweets and carbohydrates. Alaska Northern Lights makes good products, but there are many others on the market to choose from.

The second way to increase your Vitamin D levels is by eating Vitamin D-rich foods. These include fatty fish, such as cod, salmon, tuna, swordfish, sardines, and herring. Four ounces of cooked sockeye salmon contains roughly 596 IUs of Vitamin D. But, canned tuna in water contains only 68 IUs. So, you need to do your homework if you plan to get your Vitamin D this way – and be committed to eating a lot of fish!

Fish oil is also a good source of Vitamin D. For example, one tablespoon of cod liver oil contains about 1,360 IUs of Vitamin D. So, if you take a fish oil supplement, be sure to take this into consideration when calculating how much additional Vitamin D you need from a Vitamin D supplement.

A couple of other foods also contain some beneficial Vitamin D. Eggs (from chickens) contain about 44 IUs. And, one cup of maitake mushrooms contains 786 IUs of Vitamin D. (Maitake mushrooms are also a good source of prebiotics and a great way to keep your microbiome healthy.)

Have you checked your Vitamin D level lately? Do you take Vitamin D supplements? I would love to hear from you.


Last Updated: January 8, 2019

Christiane Northrup, M.D.

Christiane Northrup, M.D.

Christiane Northrup, M.D., is a visionary pioneer and a leading authority in the field of women’s health and wellness. Recognizing the unity of body, mind, and spirit, she empowers women to trust their inner wisdom, their connection with Source, and their ability to truly flourish.

Comments

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  1. Patrice
    6 months ago

    My Vit D level was low so my dr told me to supplement. My oleic acid was also low so the dr told me to take OmegaAvail Synergy instead of the fish oil I was taking. I see in your article that you say “if you take a fish oil supplement, be sure to take this into consideration when calculating how much additional Vitamin D you need from a Vitamin D supplement”. She didn’t mention me getting Vit D from the OmegaAvail.

    1. Christiane
      5 months ago

      Well you could easily check the amount of vitamin D on the label. Most people get way LESS vitamin D than is optimal. So I doubt you’re getting too much. The combo of omega 3 fats and vitamin D is a winner.

  2. Lorraine
    7 months ago

    High Dr. Northrup

    I’ve been on a Dr. prescribed protocol of 50,000 mg of vitamin D. I’m 62, live in NH and my levels were extremely low from blood work take in December 2018. Should magnesium be taken in conjunction with the D? Do you have a product that you recommend – I’m 62. Thank you for sharing your insights.

    1. Christiane Northrup
      7 months ago

      Pretty much everyone needs more magnesium. My favorite product is ReMag– balanced with ReMyte. Created by Carolyn Dean, MD, ND– http://www.rnareset.com

  3. Bob
    7 months ago

    I had no idea that you could get vitamin D from the sun. I rarely leave my house and feel really sad all the time. I guess that is because I don’t get enough of vitamin D through my skin.

    1. Christiane Northrup
      7 months ago

      Try getting out in the sun. It can help heal!!

  4. Dorothy
    7 months ago

    After I started taking vitamin D I began to experience severe pain in my joints, and in particular my legs and hips. I never experienced any pain in my joints, until I started taking vitamin D. I had to stop. I stopped taking the vitamins, the pain also stopped.
    I have heard that the pain is a sign that my body needed the vitamin. That doesn’t make any sense. If the purpose of taking the vitamins is to prevent pain, why would I take a supplement that gives me pain I never had before.
    Why did taking vitamin D cause pain that I never had before?

  5. yes I ck my vit D levels 2x yearly., started taking older people multivitamin I am 57 yrs old , ginko B mrmory supplement, Vit B complex, arthritis supplement. We live in North Pole Alaska. i am peri osteoporosis and do bone density every 3 yrs. I started working out again about 2 x weekly. I work as a caregiver for mentally and physically disabled going on 20 yrs., I am very aware I have to take care of myself i plan on retiring part time in 8 yrs . I vacation every yr in Mexico etc. my life is not centered at my work .thanks for all info and Godbless. Kathy @ Jane

  6. Gretchen M Kittelson
    8 months ago

    I just want to know if you are still taking USANA vitamins? Met you at conventions years ago. I still take, but do not attend conventions. I love reading all of your books, and your postings.

    1. Christiane
      8 months ago

      HI Gretchen, I do indeed take USANA products. The Health Pak 100, and their vitamin D. Also Procosa and Proflavenol 90. Thanks for checking in!

  7. Isabelle
    8 months ago

    I take Ageless Actives by Isagenix, which has vD3, Resveratrol, coq10 daily.

  8. Gina A. Penque
    8 months ago

    Thank You Dr. Northrup, I adore you!
    Wanted to remind all you’re breast-feeding mothers out there, that there is some research recently which states that if a lactating mother is sure to get 6400 IU‘s per day supplementation of vitamin D, that should be enough to make sure her exclusively breast-fed baby has adequate levels through the breastmilk . Doses may be able to be lowered slightly May through September in the northern areas.

    1. Christiane
      8 months ago

      Hi Gina– thank you SO MUCH for this information. It makes all kinds of sense. Christiane

  9. Mary
    8 months ago

    Can you comment on also taking calcium supplements to increase the absorption of vitamin D. Is that true or not?

    1. Christiane
      8 months ago

      It is just the opposite. You need adequate vitamin D in order to absorb calcium. But calcium is not nearly as important as magnesium which many people are deficient in.

  10. Sarah
    8 months ago

    I live in Australia. Where can I buy a vitamin D test kit?

  11. pei
    8 months ago

    Over the past 9 years, I had been taking vitamin d supplements on and off as it was causing bone pain as well as having a bent back that occasionally looks like a hunchback! It began in my late 30s and now in my mid 40s, I have develop a limp in my left leg which is cause by the osteoarthritis from my back area. X-rays show it has scarring and am concerned it could be a malnutrition problem from other causes undiagnosed. Being in northern hemisphere where sunlight is limited, it can be frustrating to get the amount of vitamin d and with low income grounds, cannot afford to go on holiday where it is sunny. I have heard that having gluten allergy (Crohn’s disease) can affect the absorption of the sunshine vitamin from the diet so may be deciding to eliminate it to see what happens.

    1. Christiane
      8 months ago

      There are many causes of metabolic bone disease. Stopping sugar and gluten are a very good start if you cannot locate a person who understands bone health. Remember that parathyroid and thyroid issues as well as gut issues are also often involved.

  12. Jane Mathers
    8 months ago

    Thank you

  13. Elaine
    8 months ago

    I am taking 2 Vitamin D3 tablets (25 mcg/1000 IU) daily as well as 2 Krill Oil capsules (500 mg). I live around the 49th parallel In British Columbia. I still seem to get sick each winter with respiratory problems (chest colds). This fall I also had a pneumonia shot, which was recommended by my dr. That didn’t seem to help, but perhaps I didn’t get it soon enough.
    Any thoughts?

    1. Christiane
      8 months ago

      You need to get your vitamin D levels checked to make sure you are taking enough vitamin D. Sounds like your levels are NOT optimal.

  14. Mariann Dunsmore
    8 months ago

    I use a Vit D product in tincture form, from a Canadian Company: St. Francis Herb Farm.
    “Vitamin D for -all”
    St Francis Herb farm.
    Vit D formula includes coconut oil, for optimum
    absorption. I know the family that began this very trust worthy company, and now their children and a huge staff have taken it over.
    Thank You Mariann D

  15. Jo
    8 months ago

    Hi! I want to thank you, Dr. Northrup, for helping all of us view women’s health from a positive perspective—so much goes right with our health and it’s important for us to know and remember this! As for vitamin D, I had my level checked at my last doctor’s appointment (it’s 29). So I have been taking 50,000 IU of vitamin D every Sunday for about 6 weeks now and I am almost ready to get my levels checked again. My question is that if I find that my vitamin D level is acceptable, should I keep taking the 50,000 IU supplement or should I take a lower amount? Also, how often should I get my vitamin D level checked? Thank you!

    1. Christiane
      8 months ago

      It generally takes 5000IU per day ( minimum ) to maintain optimal levels. Start there– and recheck in 6 months. Over time you’ll know what your requirement is.

  16. Denise
    8 months ago

    Thank you, Dr. Northrop, for the information and reminder about the importance of Vitamin D. My Ob/Gyn brought this to my attention several years ago and I tested low. I started a supplement then (Pure Synergy Bone Renewal, 2,000 IU/daily) and remember that even after I started taking supplements, I had to increase the dosage to get my levels up. I also take a fish oil supplement (Nordic Naturals Complete Omega) but I don’t see a reference to Vitamin D on the label. This is a good reminder to recheck my levels and get off “auto-pilot”. Thank you!

    1. Christiane
      8 months ago

      Good point!! thank you!!

  17. Barbara
    8 months ago

    I quickly dumped my rheumatologist when he told me that Vitamin D level of 20 ng was perfectly fine. I had to push him to test me for it. This is a doctor at a teaching and research hospital and he was the head of the department.

    1. Christiane
      8 months ago

      Sadly all too common. Which is why we all must educate ourselves and be proactive when it comes to our health. The days of ” because the doctor said so” are long gone!!

  18. Tania
    8 months ago

    Thanks for this post, Dr. Northrup! We all need to be reminded of the essential need for supplemental vitamin D in the winter months, but I’m surprised you didn’t mention the supportive co-factors needed. According to Dr. Carolyn Dean, key co-factors needed for vitamin D to be absorbed and properly utilized by the body are: magnesium (critical), vitamin K (especially K2 to properly direct the calcium flow in the body), vitamin A (fat-soluble form (retinol) found only in animal products), zinc and boron. Dr. Dean recommends magnesium chloride as a non-laxative highly absorbable form of magnesium to take, but magnesium glycinate runs a close second as a highly bioavailable, non-stimulating and non-laxative form of magnesium.

    1. Christiane
      8 months ago

      Good comment. And you are absolutely correct. Dr. Carolyn Dean is a beloved colleague of mine and , as you know, a global treasure when it comes to the importance of magnesium.

  19. Jo
    8 months ago

    Hi! I would like to thank you, Dr. Northrup, for helping all of us view women’s health from a positive perspective—so much goes right with our health and it’s important for us to know and remember this! As for vitamin D, I had my level checked at my last doctor’s appointment (it’s 29). So I have been taking 50,000 IU of vitamin D every Sunday for about 6 weeks now and I am almost ready to get my levels checked again. My question is that if I find that my vitamin D level is acceptable, should I keep taking the 50,000 IU supplement or should I take a lower amount? Also, how often should I get my vitamin D level checked? Thank you!

    1. Christiane
      8 months ago

      Hi Jo- Generally speaking — for most women– it takes a minimum of 5000IU / day ( even in the summer) to keep vitamin D levels optimal. So– I recommend that you start there. And get re-checked in 6 months.

  20. Deborah J Ripley
    8 months ago

    Hello Christiane,

    My Vitamin D Level when I had it checked by my primary care was 25. I started taking 50,000 of Vitamin D to bring my level up. I did this for 3 weeks everyday. I had another blood test which showed my vitamin D level was at
    35. Doctor stated this was fine and to stay on 2,000 a fay of Vitamin D. I have done this for a long time. I just asked to have my level checked. It appears I have not been having it checked as a routine item with my other blood. I thought this was happening. My level is 16. I do have fibromyalgia and in the last five years I have been very ill eith all kinds of muscle pain, burning in my feet, headaches, eye pain and just feeling exhausted. After reading your information Vitamin D, I had better get going on a new dose. What would you recommend to raise my level and then how much once the level is up would I take for maintenance? I know you can not prescribe to me specifically, but what would recommend for all of us out here who get told, “your blood work was fine…nothing to worry about.” Thank you for reading my letter! Miss you!!!
    Deb Ripley, Denmark, ME

    1. Christiane
      8 months ago

      HI Deb– nice to see you here. You would do better, I feel, with a vitamin D level in the optimal range ( at least 40ng/ml). You most likely need 5000IU/day for starters. Make sure you also get enough vitamin K and magnesium. In general, I tell people to get their lab values– and NOT be satisfied with ” your results are fine.” With vitamin D, you want the numbers. Same with blood sugar, insulin levels, and HbA1c ( I might add).

  21. Jane
    8 months ago

    Thank you very much.

  22. Laura Brownwood
    8 months ago

    So happy to see this article FULL of valuable information, including testing!! Adding Vitamin D to my supplements did indeed add a noticeable prevention of cold and flu. It’s comforting to know it does even more than that!! Thank you for sharing your amazing knowledge in such a great way.

  23. Nicole Lewis-Keeber
    8 months ago

    If you are unable to take fish oil, and live in a darker climate, and have absorption issues what supplement do you recommend?

  24. Mariette
    8 months ago

    Very informative article. Thank you Dr Northrup. I take 5000 iu of D3 each day. I’m 79 and I don’t get flu shots and have never had the flu. I’m in Florida 6 mos and Canada 6 mos.

  25. Claire
    8 months ago

    Is there a conversion chart for ng/ml vs IU? I eat a lot of canned salmon and sardines but also take a Vit D3 5000 IU capsule daily. Can a person take too much Vit D and what are the consequences of doing so.

    Thank you.

    1. Christiane
      8 months ago

      There is. I recommend that you get this information from the amazing website http://www.grassrootshealth.net. It contains everything anyone needs to know about vitamin D.

  26. jaci
    8 months ago

    Yes I take Thorne Labs vitamin D K2 drops every day I increase now in the winter months here in Chicago. I take 5000 units per day. Does this sound like the right amount? Thanks for the great article.
    jaci

  27. Karen
    8 months ago

    I’ve been told that you also need magnesium to help with Vitamin D absorption. Can you comment on that? Also what is the difference between D3 and D?
    thanks!

    1. Christiane
      8 months ago

      All nutrients in nature are best absorbed in conjunction with a nutrient rich diet that contains enough magnesium, vitamin K ( found in green leafy vegetables), and enough dietary fat. Vitamin D comes in a couple forms. Vitamin D3 is the form that is best absorbed by most people. The vast majority or people don’t get nearly enough magnesium.

  28. Mary Farrelly
    8 months ago

    How do I get the vitamin D to absorb into my body? I have tried megadoses of vitamin D through prescription and my vitamin D level shows little change

    1. Christiane
      8 months ago

      Get out in the sun. The body often likes to get vitamin D the way nature intended it. Also make sure to take enough vitamin K and magnesium. And enough dietary fat.

    2. Maria
      8 months ago

      The prescription (=synthetic) Vit D is not as well absorbed by the body. Better to take a natural D3 (not D2) in an oil capsel. For best absorption, you need as others have stated, vit K, magnesium,and oil. Take it together with your fish oil,or flax, borage or coconut oil for those who can’t take fishoil. 5000-10000/ day, depending on your levels. According to Vitamin D counsel, Dr Mercola and Life Extension, optimal is 60-70 – it needs to be this high to get the cancer preventing effects.

  29. Claudia
    8 months ago

    vitamin d for me is like meldonium for sharapova 🙂 i mean i was without energy for so long, a lot of problems, didn’t know what was wrong, after I discovered that my vitamikn D was low. Now, I take 1000 u/i daily and I’m superman, superwoman actually. Long live Vitamin D! 😉 I don’t know if I should stop or not coz I’m taking it for years, each day. What do you think?

    1. Christiane
      8 months ago

      Keep doing what is working. 1000IU /day is a very low dose!!

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