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How to Recognize the Symptoms of Vitamin D Deficiency

Cod liver oil capsules contain a large amount of vitamin D

Cod liver oil capsules contain a large amount of vitamin D


Prohormone: the precursor to hormones; they actually increase the efficacy of existing hormones and are eventually converted into hormones themselves.

Sterol: a steroid alcohol, which is a subgroup of steroids. Cholesterol is a sterol.

Vitamin D has been getting quite a bit of attention recently. It’s even been nicknamed “the sunshine vitamin” because our skin produces it when exposed to sunlight. Women know it as the vitamin that needs to be taken with calcium in order for it to be absorbed properly. But what exactly is Vitamin D?

Vitamin D is a prohormone sterol. It has several different forms, but we know it as vitamin D3, or cholecalciferol, which is made from cholesterol. Another form is vitamin D2, and is also called ergocalciferol, which is made from ergosterol.


An x-ray of a child with rickets.

An x-ray of a child with rickets.

The History of Vitamin D

In 1913, vitamin A was discovered in cod liver oil by American researchers Elmer McCollum and Marguerite Davis. A British doctor named Edward Mellanby began giving cod liver oil to dogs and noticed that it prevented them from developing rickets.

In 1921, McCollum modified cod liver oil by destroying the vitamin A, and repeated Mellanby’s experiment. He found that the dogs still did not develop rickets and concluded that there was another compound in the oil that prevented the disease, which he named vitamin D.

In 1923, Harry Steenbock, an American biochemist at the University of Wisconsin, found that irradiating foods and other organic material with ultraviolet light increased the vitamin D content.

Steenbock used his irradiation technique on food given to rats and found that it cured them of rickets. After patenting the invention, Steenbock’s technique was used to irradiate foods, especially dairy products like milk, which increased their vitamin D content and essentially eradicated rickets.

It wasn’t until 1936 that the chemical structure of vitamin D was actually isolated by Robert Benedict Bourdillon, Otto Rosenheim, Harold King and Kenneth Callow, all of whom collaborated on the discovery.

What Does Vitamin D Do?

Vitamin D has a number of benefits. It prevents the onset of osteoporosis, cancer and even depression. In depressed patients, it actually works as an antidepressant, alleviating their symptoms. It has also been used as a treatment for multiple sclerosis, and even asthma.

It is most well-known as the cure for rickets, which is a disease of childhood that causes the bones to soften. This softening can lead to bone fractures and even permanent deformity. The disease is caused by the body’s inability to metabolize calcium, or phosphorus, which occurs when the body is vitamin D deficient. Osteomalacia is the adult form of rickets.

In the liver, vitamin D is converted into the prohormone calcidiol. As calcidiol travels through the bloodstream, the kidneys or monocyte-macrophages in the immune system convert calcidiol into calcitriol, which is the biologically active form of vitamin D.

Once converted, it is absorbed by target cells, specifically the intestines among others. Vitamin D enhances the absorption of calcium by the intestines, which allows more calcium to be absorbed and utilized. It also allows the parathyroid gland, which maintains blood serum calcium levels, to function properly.

This image shows how calcium is regulated in the body. How vitamin D affects this regulation is shown in orange.

This image shows how calcium is regulated in the body. How vitamin D affects this regulation is shown in orange.

How Vitamin D Deficiency Affects the Body

Vitamin D deficiency can cause a number of different problems. Among the most common are osteoporosis, hypertension (high blood pressure), depression, heart disease, and rickets. A vitamin D deficiency can also increase the risk for:

  • Multiple sclerosis
  • Diabetes
  • Breast and ovarian cancer
  • Prostate cancer
  • Skin cancer
  • Colon cancer

One of the main reasons vitamin D is important is because it prevents osteoporosis. For decades we have been told that we need more calcium (especially women). To satisfy this requirement we are told to consume more dairy products, like milk. However, dairy products may actually be causing osteoporosis.

When we consume dairy products, whether it is cheese, milk, yogurt, or any other dairy product, we cause our body’s pH to become acidic. In an effort to fix this, the body uses the most abundant antacid it has: calcium. Where does it get the calcium? It’s stripped from the bones, which weakens them considerably.

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Add to that the fact that most of us are at least somewhat deficient in vitamin D, and you have a recipe for osteoporosis. So, not only are we stripping the calcium our body does have, but we’re making it difficult for the body to absorb more of it.

AgeRDA of Vitamin DTolerable Upper Intake Levels

Infants 0 - 12 months old

400 IU

1,000 IU

Children 1 - 3 years old

600 IU

2,500 IU

Children 4 - 8 years old

600 IU

3,000 IU

Males and Females age 9 - 70

600 IU

4,000 IU

Males and Females age 71 +

800 IU

4,000 IU

Pregnant or Lactating

600 IU

4,000 IU

A Note About Breast Milk and Vitamin D

It should be noted that breast milk does not contain enough vitamin D to meet the daily requirement for newborns and infants. It is a good idea to supplement breast milk with vitamin D fortified formula to prevent the possibility of rickets in newborns and infants.

Vitamin D Supplementation

The human body uses vitamin D3 much more efficiently than D2, which is why most supplements are made from D3.

The two main sources of this vitamin are fish liver oil, and oil that has been extracted from wool. You can tell which source your supplement comes from by looking at the label on the back of the bottle.

If the label reads “fish oil” in parentheses then it’s obviously made from fish oil; however, if the label reads “Vitamin D3 (cholecalciferol),” then it’s made from wool oil, which is preferred by vegetarians. Interestingly, animals can obtain vitamin D by licking their fur.

Vitamin D supplementation is highly recommended for those who are not exposed to sunlight frequently, those who are overweight, or those who have dark skin (darker skin blocks 95 percent of ultraviolet light from reaching the deeper tissue, which makes manufacture of vitamin D all but impossible).

Our diet alone cannot give us the amount of D3 we need on a daily basis. Our skin typically manufactures about 10,000 to 20,000 IU of D3 when exposed to sunlight during the day. This is much more than the U.S RDA (recommended dietary allowance).

Tuna is a good source of vitamin D

Tuna is a good source of vitamin D

There are some foods that contain vitamin D and can be eaten to augment exposure to sunlight. These foods include:

  • Catfish
  • Mackerel
  • Salmon
  • Sardines
  • Tuna
  • Eel
  • Eggs
  • Beef liver
  • Fish liver oil

Possible Side Effects of Vitamin D Supplementation

While side effects are possible, many experts in the medical community have exaggerated their findings. Many reports have warned that taking vitamin D supplements in higher dosages can cause calcification of soft tissue such as the lungs, kidneys and heart, which is called hypercalcemia. However, the length of time this takes to occur would be such that other symptoms of toxicity would show before any serious damage would be done. Symptoms of hypercalcemia include:

Do You Have Vitamin D Deficiency?

  • Nausea
  • Vomiting
  • Anorexia
  • Weakness
  • Polyuria (excessive urination)
  • Polydipsia (excessive thirst)
  • Insomnia
  • Nervousness
  • Pruritus (intense itching)
  • Renal failure

Treatment of hypercalcemia involves discontinuing the vitamin D supplement and restricting how much calcium is consumed. If you are currently taking any medication, or if you suffer from liver or kidney disease, it is recommended that you talk with your physician before starting vitamin D supplementation.

© Copyright 2012 - 2016 by Daughter of Maat ALL RIGHTS RESERVED

This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.


Glenn Stok from Long Island, NY on February 28, 2016:

Very useful hub. I discovered my level of Vit D was low when I looked at my last blood work report. The interesting thing is that my doctor never mentioned it to me. But when I asked him about it, he agreed with me when I asked if I should take Vit D supplements.

The problem is that most doctors don't pay attention to this important aspect. And they are not trained to know what you talked about in this hub. Only naturalpathic doctors would know this. That's why it's so important for us to educate ourselves.

Tammy from North Carolina on August 24, 2013:

A few years ago I had a deficiency. It is amazing how it can affect your health so adversley. Well researched and presented!

Mel Flagg COA OSC (author) from Rural Central Florida on February 08, 2013:

You're welcome!1 Many people don't know that you can actually get it from food. It's just faster to get your daily amount by spending 15 minuted in the sun. :)

Cuttler from HubPages on February 03, 2013:

Great info...never knew that vitamin D could be found in food. Always thought it to be a sun thing only. Thank you for sharing this

Mel Flagg COA OSC (author) from Rural Central Florida on December 08, 2012:

@mizjo Thank you! I know what you mean, even though I live in the Sunshine state, I don't get out in the sun much. I take about 2,000mg of vit D a day. It really makes a huge difference in my mood and appetite.

mizjo from New York City, NY on December 06, 2012:

Very well researched and informative hub, DOM. It's great to know that with my 1200 IU of Vit. D3 a day - which is included in my Calcium capsule - I am preventing so many diseases. I'm not getting enough sunshine these days because it's so cold I'm not inclined to go out much.

Thanks for all the info.

Mel Flagg COA OSC (author) from Rural Central Florida on November 28, 2012:

@phoenix I'll bookmark it and check it out when I get a chance :D

Zulma Burgos-Dudgeon from United Kingdom on November 25, 2012:

Another Vit D hub for your perusal:

Mel Flagg COA OSC (author) from Rural Central Florida on November 19, 2012:

@gjcody Thank you!! Where are you located? I suspect a wintery area? :D

GJCody from Pittsburgh on November 18, 2012:

Enjoyed your article on Vitamin D3 ...It is definitely a vitamin that is very needed in my area. Thank you for sharing Daughter of Maat. My best to your success and health!

Mel Flagg COA OSC (author) from Rural Central Florida on November 16, 2012:

Indeed!!! Thank you for the link!!

Zulma Burgos-Dudgeon from United Kingdom on November 14, 2012:

Hi DOM. I thought you might find this hub interesting:

Mel Flagg COA OSC (author) from Rural Central Florida on November 11, 2012:

@SaritaJBonita Dark skinned individuals also have problems making vitamin D from sunlight, mainly because the pigment doesn't allow the UVB rays to get all the way down into the deep tissue. And I know what you mean by the achiness!!

Mel Flagg COA OSC (author) from Rural Central Florida on November 11, 2012:

@PWalker281 Thank you!! I aim to make all my hubs on vitamin supplementation as thorough as possible, and I'm glad to know that I was successful on this one because it was a bit more difficult for me to write. We get quite a bit of rain here in Florida during the summer months, and I usually up my D dose during that time, so I know what you mean!

Mel Flagg COA OSC (author) from Rural Central Florida on November 11, 2012:

The D vitamin doesn't just have to be for calcium. It does serve several other functions because it is present in tissues such as the brain, heart, pancreas, white blood cells, and gonads, not just in the bones. And actually, 2,000IU a day isn't really a lot. Some epileptics have been known to take over 4,000IU a day.

As for your kidney stones... First I'M SO SORRY!! lol Not to compare you to an animal, but my dog had kidney stones, and although she had a high pain tolerance, I knew it was REALLY painful. You may want to look at your vitamin C levels for those. Here's why: it's a myth that vitamin C actually causes kidney stones. It's just the opposite. Vit C prevents calcium from binding with urinary oxalate which keeps stones from forming. The suggestion to increase Vit D may actually be an attempt to get your body to distribute the calcium rather than solidify it in the kidneys. But they may be suggesting the wrong vitamin. Cloudy urine, which is usually cloudy because of crystalline and organic sediment, is a sign of low levels of vitamin C. After beginning supplementation with vit c, the cloudiness usually clears up in a matter of hours. That sediment solidifies into stones.

Thankfully, vitamin C is the SAFEST supplement you can take, any excess vit C you consume is simply passed in the urine, which in your case, would be a good thing. That vit C may help break up those stones and make them easier to pass. I have a hub on vit C if you need info on how to take it. Let me know what you think of my wacky theory here lol

SaritaJBonita on November 09, 2012:

I have chronically low levels of Vitamin D, even in the summer time. I'm pretty dark-skinned (I have the French-Canadian/Native American olive toned skin). But, vitamin deficiencies run heavily in my family. When my levels run low I can usually tell, because I get such horrendous joint pain. I'm so achy that I feel like I have the flu. I take 2,000 i.u. a day.

@newusedcarssacram, I wish I could get Vitamin D from the sun year-round, but in the northeast the winter sun provides almost no Vitamin D, even when it's sunny outside. Perhaps I should take an annual medically-necessary vacation to the beach?

@ImKarn23, Magnesium is also great for preventing kidney stones! I've luckily never had one (although they run heavily in my family). I take Magnesium for migraines, and I was told that it has the added benefit of preventing kidney stones. Look it up..

Mel Flagg COA OSC (author) from Rural Central Florida on November 08, 2012:

@Ronnie, indeed, both vitamin D and vitamin C deficiency can cause depression! (So can B vitamin deficiency!) So glad my hub helped you!! :D That's why I write, to help people. :)

Mel Flagg COA OSC (author) from Rural Central Florida on November 08, 2012:

@chef-de-jour. I understand about the tuna, hubby and I are vegan, so we have to take our vitamin D via a supplement, or by tanning lol. My parents were of the cod liver oil era. A spoonful of liver oil daily I believe was the dosage. Yuck... lol

Mel Flagg COA OSC (author) from Rural Central Florida on November 08, 2012:

@Heather Says, Indeed fair skin very well could be to blame. Most people with fair skin do not process vitamin D efficiently enough to provide the body with the required amounts. Try cutting down on the milk and replacing it with either a supplement or lots of calcium containing veggies like broccoli, and kale. If you're lactose intolerant and don't know it, you may not be getting either the vitamin D or the calcium from the milk. Vitamin D deficiency may actually be a result of lactose intolerance that is asymptomatic. :D

Mel Flagg COA OSC (author) from Rural Central Florida on November 08, 2012:

@newusedcarssacram Natural vitamins are always better, but supplements do have their place for those who live in areas that are not exposed to sunlight due to long winters, etc. Unfortunately, we can't get enough natural vitamin D from our diet alone. But I agree, mother nature knows what she's doing much better than we do!!

PWalker281 on November 08, 2012:

This is one of the most informative and well-written hubs on the subject of Vitamin D I've ever read. I recently started re-taking a vitamin/mineral supplement after a long hiatus (I've been taking them since the 70s but stopped for a couple of years). I had to check to see if D was included, and it is, 1,000 IU in the form of cholecalciferol (calcium, too). If I hadn't read this hub, I would not have known that this is D3.

Despite the fact that I live in Hawaii, I live on the windward side of Oahu which gets a lot of rain and is often cloudy, so I probably need to take it, especially since I have a dark complexion. Dr. Oz is a big fan of D3 supplementation which is where I first heard about its importance.

Voted up and sharing.

Karen Silverman on November 08, 2012:

Vitamin D is an issue for me. Maybe you can help where Dr's are afraid to go..

First of all - i happen to live in THE coldest city in the entire world..(google Ain't i lucky? lol

I have been diagnosed with anemia once in my life- but - that was waaay back when i was a gymnast training 6hrs/day..

It never re-occurred - but - i've recently been told to double my D intake to 2000mg/day, BUT - i don't take calcium supplements..

i'm VERY prone to kidney stones and actually have about 7 just waiting to (i tell people i just had a KID....NEY STONE..(not much different in pain...sigh..)..

Doctors are afraid to recommend calcium - so - what good is the Double D?

Really interesting hub! Thanks

Dim Flaxenwick from Great Britain on November 08, 2012:

Hi there DOM,

What a wonderful, informative article..... One so close to my heart and my physical needs.

20 years of living in a hot country , direct sunlight on my body every day, I have been fretting since my 1st day back in Britain in 2010. This has helped and encouraged me a lot. I thought I knew all I needed to know about Vtiamin D, yet I had no idea about depression. I have been assuming I am merely depressed because I did not want to leave my warm lovely island and I hate being up here in the cold North of England.

You´ve helped me to think again.

Bless you for this hub.

A very grateful, Ronnie(aka Dim),.....

Andrew Spacey from Sheffield, UK on November 08, 2012:

Interesting, thank you. Cod liver oil tablets were a staple pre school send off gift from my mother when we were children- I can still taste them now! - but what benefits for us in a mostly gloomy grey climate! (north England). Some great information. I've recently given up eating tuna - on account of the uncertainty around the killing of dolphins and the like - but I shall be more aware now after reading your hub.

Heather from Arizona on November 07, 2012:

Maybe my fair skin is also to blame? Like carol said, I'm also from Arizona and I drink tons of milk-- a deficiency was really a shocker.

newusedcarssacram from Sacramento, CA, U.S.A on November 07, 2012:

Really helpful hub you have shared. But I feel natural resource of Vitamin D is the best way to get. We should not depend on pills.

Mel Flagg COA OSC (author) from Rural Central Florida on November 07, 2012:

@Heather Says I too noticed a change in my mood when I started taking a vitamin D supplement. I also noticed a change in my appetite. I'm so fair skinned that I don't process vitamin D as efficiently as I should, which I didn't know until I did the research for this hub! (And my hubby wonders why I love research... sheesh... lol)

Heather from Arizona on November 07, 2012:

Great hub! So interesting. My Obgyn recently started me on vitamin D because I have a deficiency, apparently. I just now realized, while reading your hub, that my mood picked up around the same time. How about that!

Mel Flagg COA OSC (author) from Rural Central Florida on November 07, 2012:

@vocalcoach Thank you! There has been quite a bit of emphasis placed on vitamin D recently, I think that's mainly because of the avoidance of sun exposure. The threat of skin cancer has made it much more likely that people will suffer from vitamin D deficiency. At least that's my opinion. :D Thanks for voting and sharing! Greatly appreciated!

Audrey Hunt from Pahrump NV on November 07, 2012:

An excellent source of information on vitamin D.

There seems to be more importance placed on this vitamin today than ever before. Thanks for keeping us up to date. Up, across and sharing.

Mel Flagg COA OSC (author) from Rural Central Florida on October 28, 2012:

@peterkua Indeed!! Mother nature knows best. There's a reason our skin produces vitamin D! :D

Peter Kua from Malaysia on October 28, 2012:

Very well written and thanks for the info on vitamin D. Really, nothing beats the sun when it comes to soaking in this vitamin. To those of us living in tropical climates, we should think our lucky stars.

Mel Flagg COA OSC (author) from Rural Central Florida on October 27, 2012:

@Billybuc Thank you for stopping by and commenting. I've become a bit of a vitamin fanatic recently... lol

Mel Flagg COA OSC (author) from Rural Central Florida on October 27, 2012:

@Duchessoflilac1 Did you get the results of the test back yet? Unfortunately, people who live in northern states are much more susceptible to vitamin D deficiency because of the winter months!

Mel Flagg COA OSC (author) from Rural Central Florida on October 27, 2012:

@B. Leekley Thank you!! Greatly appreciate the shares and votes!!

Mel Flagg COA OSC (author) from Rural Central Florida on October 27, 2012:

@Carol actually it doesn't surprise me at all. I live in Florida and although I haven't been tested, I'm fairly certain I'm deficient! lol But you are absolutely right, it is much more common than we're led to believe. Thanks for commenting and voting!

Mel Flagg COA OSC (author) from Rural Central Florida on October 27, 2012:

@Janine Thank you! I haven't had my levels checked, but after working on this hub, I think I will. Even though I live in sunny Florida, my skin is very pale, so I don't go out in the sun all that much (plus I REALLY hate mosquitoes). How much vitamin D do you take a day?

As always thanks for sharing! :D

Mel Flagg COA OSC (author) from Rural Central Florida on October 27, 2012:

@RichieMogwai I've just recently become a vitamin freak. I keep researching the subject constantly and I end up writing about it in an effort to get the word out. Yes, tuna is full of vitamin D, I didn't know that either until I was doing the research for this hub! :D

Bill Holland from Olympia, WA on October 27, 2012:

Very useful and informative! Important information here, much of which I did not know. Thank you!

Rebecka Vigus from Nancy KY on October 27, 2012:

This was good. I was just tested for a potential Vitamin D deficiency

Brian Leekley from Bainbridge Island, Washington, USA on October 27, 2012:

Good information. Thanks. Up, Useful, Interesting, and shared with followers and on social networking sites.

carol stanley from Arizona on October 27, 2012:

Good hub on Vitamin D. This will amaze you..we live in sunny Arizona and my husband actually had a vitamin D deficiency..more common here than you think. Voted UP.

Janine Huldie from New York, New York on October 27, 2012:

Very informative Melissa. I was told after having my kids that y vitamin D levels were low and to take a supplement for it. So I was aware from researching it quite a bit of what you wrote here, but truly a great resource for those who don't know too much about. Great job and have voted and shared all over!!

Richie Mogwai from Vancouver on October 27, 2012:

Thanks for sharing this information-packed hub. I am a vitamin freak, I guess my mom raised me and the rest of the kids that way. However, I did not know that tuna is rich in vitamin D. It's always great to catch new information and apply it in our lives.

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