Boost Your Fertility with Vitamin D

Infertility has many causes, but one that is often overlooked is a vitamin D deficiency. Our bodies need ample amounts of this essential vitamin in order to produce estrogen (in both men and women) as well as for insulin production.

What is Vitamin D?

Vitamin D is a fat soluble vitamin and exists in several forms. Some of these are basically inactive in the body and have limited ability to function.

Why is it important for fertility? Well, you need it in order for your body to produce sex hormones. And without the right amount of hormones in your system, you can suffer from pcos, PMS, and infertility. Vitamin D is also key in regulating cell growth and deciding how those cells grow.

A study was done by the Yale University School of Medicine (source) with 67 women suffering from infertility. Only 7 % of them had normal vitamin D levels! 7%. The rest had either insufficient levels or an actual clinical deficiency.

Dr Lubna Pal, from Yale, said: “Of note, not a single patient with either ovulatory disturbance or polycystic ovary syndrome demonstrated normal Vitamin D levels; 39 per cent of those with ovulatory disturbance and 38 per cent of those with PCOS had serum 25OHD levels consistent with deficiency.

“Given the pandemic of Vitamin D insufficiency, if indeed our observations are substantiated, aggressive repletion with Vitamin D may emerge as an alternative approach to facilitate ovulation resumption with minimal to no risk for ovarian hyperstimulation syndrome or multiple pregnancy.”

Those are some pretty large percentages too – almost 40% of the women with ovulation problems had clinical deficiencies. Obviously, vitamin D is important to our reproductive system.

Where to Find Vitamin D

Food is the best source of vitamin D, and the easiest way to consume it is to eat fatty fish, eggs, and grasssfed meat and dairy products. If you do have a hard time getting it in your diet (don’t have access to clean fish), supplementing with cod liver oil is also helpful in making sure you’re getting enough. (another great reason to take cod liver oil is the fact that it has the right ratios of vitamin A and D in it which help both nutrients absorb correctly) And just make sure if you buy supplements that the ones you buy contain vitamin D3 and not D2 which actually does not raise the blood levels of vitamin D.

And as most of you know, you can also get vitamin D from the sun. About 15-20 minutes of exposure (without sunblock as it blocks the ultraviolet light needed for vitamin D production) a day can be very beneficial. The sun actually causes your skin to produce vitamin D3 which is then converted by the liver and kidneys to the active hormone form of vitamin D. With proper sun exposure, your body can actually produce up to 10,000-25,000 IU of the vitamin.

You can also learn more about how to include vitamin D rich foods by reading the Fertility Diet series.
Donielle Baker

Donielle Baker

owner and editor of Natural Fertility and Wellness at Natural Fertility and Wellness
Donielle believes women can learn how to heal their bodies & balance their hormones through natural methods. An advocate for natural health, she has a passion for nourishing/real food nutrition and natural living. Her personal background includes both infertility and miscarriage and she started Natural Fertility and Wellness in 2008 in order to share all of the information she found helpful in her journey to heal from PCOS and overcome infertility.
Donielle Baker
Donielle Baker
Donielle Baker
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    • Evie says

      I read this article about 6-7 months ago. I have PCOS and I’ve tried everything, including formal fertility treatment to get pregnant. I was successful once, which ended in miscarriage. I’m so happy to report that with no fertility treatment, I’m now naturally knocked up! I supplemented with Vitamin D for a few months. I started by taking 10,000iu daily for two weeks, then I began dropping the amount down by 2,000iu per week without going below 2,000iu per day. I’m currently almost 3 months pregnant. The pregnancy is going perfectly well. I’ve already had a few ultrasounds that show a healthy heartbeat and beautifully growing baby! Just wanted to share some hope!

  1. Katie @ Kitchen Stewardship says

    I’m finally getting together a co-op to get grassfed meat – so excited! My 11-month-old daughter was in the sun the other day – just 10-15 minutes – and she got a bit pink. I’m hesitant now! It was right at midday, picnic lunch time, so I know I should be more careful about timing. But what to do when you’re just outside and it’s the wrong time? I don’t trust the chemicals in sunscreens…do you have any natural alternatives?

  2. Anonymous says

    This is very interesting about vitamin D and infertility.

    I've been irregular my whole life except for an exchange in university where I went to a tropical country, so this makes sense. I've been TTC for one year, so I'm going to get me some vitamin D supplements today.

  3. carrie says

    i’ve been under treatment for infertility for 8 months. last week my doctor tested my vitamin D level. he just called to tell me i was waaaay below the healthy level and told me to go out and buy a vitamin d3 supplement! from what i’ve read on the internet of the research that’s been done, i’m hopeful that this can make a difference. funny thing is i live in Arizona- the so-called “valley of the sun”, but apparently i’m spending too much time inside 😉

    • donielle says

      @carrie, I would definitely try and get some fermented cod liver oil from then! It’s high in vitamin D as well as A (which I’ve recently found out is essential for absorbing vitamin D). Taking the oil plus a D3 supplement should really help bring your levels up! Hope it’s the answer you’ve been looking for!

  4. says

    Great information! Just to add: Vitamin D is technically a hormone, so unless one is deficient, one must be careful about obtaining too much from a supplement (it accumulates in your body, rather than eliminating if not needed). Also, the BEST source of Vitamin D is the sun. But we must get direct sun on our bodies for 5-15 minutes a day, a few times a week- that means no sunblock! I live in sunny Southern California, and was shocked when my vitamin D levels were low a few years back.

    Good luck everyone!
    Jenny :)

    • donielle says

      @Jenny, Yes, definitely one of those things you don’t want to much of. :-) One of those crazy “balance” things. Thanks for the reminder!

  5. says

    Great site Donielle! Happy to see that you are bringing up the importance of vitamin D.

    I live in Canada and for half of the year we are indoors and when we are outside in the winter, we are totally covered up…resulting in an obvious lack of vitamin D. I recommend supplementation in the form of D3 to all of my clients (for fertility enhancement and general health). I personally take 5000IU (with food) in the winter and 2000IU in the summer.

    I also encourage people to get their blood levels tested for vitamin D (25 hydroxy D). This is a simple addition to any regular blood test and can help determine the amount of supplementation necessary. It also reduces the chance of vitamin D toxicity (which is very, very rare…occuring only with certain medical conditions).

    I will be sure to send my fertility clients to your site to take advantage of your great resources!

    All the best.


  6. says


    I practise Traditional Chinese Medicine & Acupuncture as well as Orthomolecular Nutrition with a focus on natural fertility enhancement, menstrual issues and menopause in Toronto, Ontario.

    Let me know if you ever need an expert in TCM to comment or if you would like to post some of my articles on natural fertility for your readers.

    Take care!


  7. linda says

    Donielle, I am experiencing secondary infertility (did multiple IVF’s) and just found out vitamin D deficiency. Do not have ovuation problems or poly cystic ovaries. What then would be the possible correlation between the deficiency and my lack of success if everything is checking out normal –FSH etc.?

    • donielle says

      @linda, One of the biggest things that Vitamin D does is to help cells decide how and when to grow.

      I’ve also noticed that there seem to be a discrepancy in hormone tests and I tend to think that ‘normal’ for one woman may not be ‘normal’ for another. I went 2 years without ovulating once, had my hormones tested and they came back as ‘normal’…..really? Of course that’s not to say that your tests are not, just giving my personal experience there. :-)

  8. says

    I loved the article, so I hate to have to rain on the parade, but the information about cod liver oil is wrong according to the latest research. Cod liver oil has high levels of retinol, which is the form of vitamin A which the body can’t get rid of. Beta carotene is the form of vitamin A that the body can more easily push out of the body in case there’s already enough.

    The vitamin A in cod liver oil actually cancels out the effectiveness of vitamin D, and can lead to other health problems. See here:

    From the link:

    “However, hidden on page eight is one sentence and a small table, which shows that the benefits of vitamin D are almost entirely negated in those with the highest vitamin A intake. And the retinol intake did not have to be that high in these older adults to begin to negate vitamin D’s effects, about 3,000 IU/day.”

    • donielle says

      @Adam, Adam, I thank you very much for your thoughtful and thorough response to my post. But I think we’re going to have to agree to disagree. :-)

      You see, I feel that most people are deficient in retinol, the type of vitamin A that is so important to how our body functions. Beta carotene on the other hand has to be consumed at about 6 times the rate of foods containing retinol for the body to try and convert it as the same amount. People with poor health need even more to make that conversion.

      I also tend to agree with the research posted at which specifies that A and D need to be taken together to prevent toxicity of either one. It also makes sense int eh aspect that when found naturally in foods, they are found together.

      Again, thank you for your thoughts – I always appreciate hearing someone else’s point of view and looking into what they’re saying when they come off as an intelligent human being.

  9. Ame says

    I have been TTC for a very long time now (years). I’ve been on clomid, I’ve had my tubes checked, I’ve had surgery as they thought I had endometriosis (which I did not), in fact they said I was perfect inside and it’s “unexplained infertility”. I do not have normal cycles. I was sick a few weeks ago & went to the doctor. My family doctor moved so there was a new one. She was more interested in getting my vitamin levels for some reason so ran some blood work. Everything was perfect she said except my Vit D levels. I forgot the #’s you’re supposed to be between but I was lower. Anyway I got to reading this and I’m really hoping that with me taking the 50k units of Vit d once a week for 6 weeks then moving on to an over the counter vit d suppliment everyday after this will do the trick!!! Is there any other advise you have to offer? My husband has been checked & cleared… he will be 32 in a few days & I’ll be 26 in a couple of months.

  10. Julie says

    It is so great to find your website. I too have suffered from infertility/miscarriage. My ob/gyn did many many tests and never tested for vitamin D. I only found out about my deficiency when doing a routine physical at my family doctor. He strongly believes that my deficiency is to blame for the fertility problems. I’ve been taking 5000 IU per day now for a month. I really hope that my levels come up and that I get pregnant soon. Good luck to all of you out there!

  11. Julia says

    I had recurring “unexplained” miscarriages until my vitamin D levels were raised over 60ng. Now I have 3 kids. I agree with Adam about caution concerning too much retinol. Certain prenatals have too much.

    • Leslie says

      @Julia, Hi. How much Vit D did you take to get your vitamin D levels to get to over 60ng?

      I had mine tested and they were at 22. For 6 weeks I took between 3,000IU and 5,000IU and when vit D was retested it was only 33.


      • Ana says


        Hi Leslie.

        I was at 24, that is deficient in February, the first time I checked my vitamin D levels, and I live in a sunny place, and took everyday 2000IU with a supplement. Then I thought it was the supplement that wasn’t good enough, but as I wanted to raise my levels to at least 60, I did a research and began to take 10000IU, today researches show it is totally safe, for 3 weeks, and checked the levels: 29, so I took 10000 for one more week and 5000 for near 3 months, and then I had 64. So I take now 2000 per day and expose to the sun several times a week, cause I want to keep that levels.

        Perhaps that explains why I haven’t been able to conceive, and it’s been only 5 months ago. That’s my experience with Vitamin D. The other thing I found out is that vitamin D has to be taken with fat, as it is fat soluble, so if you don’t, as I did, eat any fat, your levels of vitamin D will probably be low.

        Good luck

  12. Courtney says

    Donielle, I would be interested if you have any take on this: I had my level checked last yr at a physical (I am an RN and demanded it). I was low, 21, even coming off summertime. I did a bunch of research and learned I needed to do large doses to boost, then do maintenance. I took D3 with chelated Mag, 50000 per week for about 6 or 8 weeks, then I backed off to 5000-10000 per week. I got my level up to 48 after 3 months. Oddly though, I experienced an “annovulatory” cycle that month (I was not TTC at this time). I have 1 child and was rock solid regular all of my fertile life. The MD thought nothing of the Vitamin D. Any feelings on this? Seems like I had a paradoxical effect, or just coincidence?? However, I am now TTC for #2 and am on month 8. My periods since that time of a good level actually shortened to 21-25 days. I am charting now and dealing with a short luteal. My level is currently low again at 31 (I stopped the maintenance dose months back).

    • donielle says

      @Courtney, I guess i dont’ have any major words of wisdom for this, other than it isn’t uncommon to have an annovulatory cycle every now and again. So maybe it was coincidence….? Another issue might be that long term supplementation can also lead to other nutrient deficiencies.

  13. Evie says

    I read this article about 6-7 months ago. I have PCOS and I’ve tried everything, including formal fertility treatment to get pregnant. I was successful once, which ended in miscarriage. I’m so happy to report that with no fertility treatment, I’m now naturally knocked up! I supplemented with Vitamin D for a few months. I started by taking 10,000iu daily for two weeks, then I began dropping the amount down by 2,000iu per week without going below 2,000iu per day. I’m currently almost 3 months pregnant. The pregnancy is going perfectly well. I’ve already had a few ultrasounds that show a healthy heartbeat and beautifully growing baby! Just wanted to share some hope!

    • donielle says

      @Evie, {squee!!} Congratulations!!! I’m so exited for you! Praying the rest of your pregnancy goes without a hitch and that you feel healthy and strong throughout. Thanks so much for sharing your success story. :-)

  14. Megan Winter says

    I found out about 3 months ago that I am vitamin D deficient. My husband and I were diagnosed with unexplained infertility 7 years ago. I had never been pregnant until about a month ago. I had only been on vitamin D supplements for 2 months! Unfortunately, we had a miscarriage but we are VERY hopeful the vitamin D was the culprit and we will get pregnant again soon. Thanks for sharing this information with infertile couples.

    • kim perez says

      I can testify to vitamin d being a fertility booster. I went for an annual physical and was told my vitamin d levels were too low. I went to a health food store and purchased liquid vitamin d. Taking 5000 iu per day, I was pregnant within 3 weeks from the start of consuming the liquid form of vitamin d. Prior to my dr. appt. we were ttc for one year. Loosing faith, I decided to stop ttc. I can stand here today and say that I am now two months pregnant.

  15. Jessica says

    I am loving your site here, Donielle! Being raised on a nearly self-sufficient farm, I have always believed that “the more natural your food, the better,” and I share that with anyone who will listen. I can also attest to the importance of Vitamin D for fertility. After a couple years of irregular cycles and TTC for an additional year, I was finally referred to an endocrinologist who diagnosed me with Vitamin D deficiency – not because I wasn’t getting enough, but because my body wasn’t processing it correctly. My doc put me on medication and I was amazed at the difference. Not only did my body start a regular cycle, but I slept through the night for the first time in years, and my muscles were no longer sore all the time. I never would have thought little things like that could signal a deficiency in your body. And to top it off, we got pregnant within the first month on the medicine! We now have a very healthy little boy. Any time friends tell me about having irregular cycles or infertility problems, my first response is almost always “Have you had your Vitamin D levels checked?” Thanks for highlighting the importance of Vitamin D, keep up the good work!!

  16. Jenn D says

    Hi All!

    I am 38 and at the end of last year, I had my 4th IVF treatment. This one was with donor eggs, as my FSH is 27 and I didn’t respond to IVF drugs. The IVF treatment at the end of last year, was the first time it actually did work, but then resultsed in miscarriage at 5 weeks. I JUST (after 4 fertility treatments in 4 countries) had my Vit D level checked and it was 12! I am also being checked for adrenal insufficiency–which I read can also cause fertility issues.

    Any words of advice?

    THANK YOU! :-)

  17. Laura W. says

    Wow, thank you for this article! My hubs and I have been ttc for almost 4 years now. He’s been checked out and he isn’t optimal, but there is something there, which makes me wonder if it’s actually me.

    I had a full physical 3 weeks ago and had them check my labs and it showed I was extremely deficient in vitamin D (we do live in Alaska! LOL). My doc is having me do 50,000 iu weekly for 12 weeks and then test again. Like one of your commentors, this first month, I didn’t ovulate. Having read her comment, I’m wondering if it’s due to the sudden supplementing. Either way, your article really made me think and it gave me another line of thought. :)

    Thanks again!

  18. says

    I’m very concerned that you are recommending cod liver oil for people ttc. It has high levels of vitamin A which can cause problems for a developing baby.

    • donielle says

      @Anonymous, Yes, there is controversy concerning vitamin A. But the Weston price folks have found that traditional peoples consumed much more than we do today and had no issues. Most studies are also done with synthetic vitamin A which makes a big difference as well. But you can also consume cod liver oil safely during TTC and pregnancy by not taking a dose that will put you over 10,000 IUs of vitamin A a day to stay on the “safe” side. Consuming vitamin A along with vitamin D and especially the vitamin K2 in the cod liver oil/high vitamin butter oil combo also helps the body absorb and utilize all of the nutrients, making overdosing not as easy as it would be if you were just taking high doses of vitamin A.

      Thank you for sharing your thoughts!


  1. […] The other day I had some blood work done – turns out I’m extremely Vitamin D deficient. Read this article – it blew my mind. Not saying it’s the end all to my problems, but could definitely be playing […]

  2. […] My vitamin D level was low also.  One of these days, I’d like to read more about vitamin D, but I know it’s really important for lots of stuff.  How’s that for scientific?  Well, that’s what Google’s for, right? :)  In listening to my doctor, I did manage to write down that vitamin D is related to immunity, depression, heart disease, our bones, and dopamine levels in the brain.  A friend who also visited this clinic said his doctor related vitamin D to a hormone – its functions are that important.  It also has a role in fertility. […]