Primary Location

1101 10th Ave N,

Clear Lake, IA 50428 US



9:00 am - 5:00 pm


9:00 am - 5:00 pm


9:00 am - 5:00 pm


9:00 am - 5:00 pm


9:00 am - 5:00 pm






We value our patients' experience at Voortmann Chiropractic & Natural Body Restoration. If you are currently a chiropractic patient, please feel free to complete the following Client Experience Questionnaire. The Questionnaire is in Adobe Acrobat format, and requires the free Acrobat Reader to view.

Download & Print Questionnaire

Dr. Kathleen Voortmann
Your Clear Lake Chiropractor

What our Clients are saying?

For 15 years, I have been struggling with digestive issues, low energy, poor sleep, brain fog, back pain, and anxiety. For these 15 years I sought doctor after doctor, diet after diet, and pill after pill with no success. A month before hearing about Dr. Voortmann I remember sitting on the couch in tears watching my toddlers play. I was devastated because I was in so much pain and had no energy to play with them.

NOW, a year later after working with Dr. Voortmann my life has done a 180! Voortmann said it would take time and discipline to peel back all the health layers, but we are seeing improvements for the first time in 15 years! I have ENERGY again! I don't spend the afternoons in the bathroom anymore! My back pain is gone! And, I can eat without all the pain and IBS! We still have more journey ahead but are excited to have help and improvement!

Nathan Hawley


I saw an advertisement for Dr. Voortmann and decided to spend some money on my health. AM I GLAD I DID! Within several days of some new supplements, a couple of chiropractic treatments, and changes to my diet, I began feeling noticeably better. My mind was clearer, I felt better after the 1st month than I had in a few years.

Now I’m in the end of my 2nd month. I have lost 12 pounds for the 20 I want to lose. I feel more alert, sleep less, and overall feel better.

As a big bonus my seasonal allergies have been about 80% better too!

Thank you Voortmann Clinic

 Bob S.


What was it like before you came in to see us? After many years of alternative medicine treatments and supplements, I came to Voortmann Natural Improvement Center with severe adrenal fatigue and was found to have low thyroid, weight gain, brain fog, low immune system and many skin breakouts.

How is it now? Today, I find I am joyful due to improvements in all of the above areas. My immune system is improving and my outlook is I will overcome my health issues and continue to have a blessed life!

-Marlise S.

I was having heart palpitations 24/7. There would be about 4 days through a month when I wouldn’t have heart palpitations. Most every night I would sleep in a recliner as the heart palpitations would not be as severe as sitting more upright. Now, I have heart palpitations a couple times a month. Dr. Kathleen has me taking Thyrotropin and E manganese for hormonal problem and Parotid for chlorine for my heart. I started coming to Voortmann clinic 5 months ago. There were times I was going to quit taking my supplements and end my visits because it didn’t seem to work. But, Dr. Kathleen was optimistic about helping me that I continued on in her care. . Having heart palpitations constantly can be discouraging but palpitations are better now. I have more energy and emotionally feel better I am so glad I came to Dr. Kathleen’s clinic.

-P. Johnson

I had pain in the left hip that not even spinal surgery would help. After 3 months of Nutrition Response Testing, I have no pain in the left hip and can walk better.


Before coming to Voortmann Chiropractic and Nutrition, I used to sleep 15-20 hours a day, had no energy, no appetite, no emotional stability, and a lot of physical pain. I felt like I should be staying in a nursing home or at a hospital. Now, I sleep half as much and feel like I could run a marathon. I eat 5 small healthy meals a day. I have had no physical pain for about 2 weeks and am finally nearing emotional stability. I feel my age and possibly younger. Life is so much easier now than ever before.

-Janessa Reding

Before I started Dr. Voortmann’s Program, I had severe headaches on a daily basis. I was taking ibuprofen at least twice a day. Some days, the HEADACHES were so BAD I couldn’t even think at work. The headaches are gone and I feel a lot BETTER. I may have an occasional “mild” headache, but nothing that I can’t handle.

-John S.


Before my treatment with Dr. Voortmann, I was so tire & unmotivated to do the simplest tasks. I would use my lunch breaks to take naps and lay on the couch until bed time. I constantly felt uncomfortable, inflamed, and BLOATED. I sought treatment for what I thought was digestive issues- my plan focused on other areas. I was falling asleep easily, but would WAKE UP for a 1-2 hr period a few nights a week.

I'm honestly SHOCKED- my treatment plan was super affordable and has already make an IMPACT. I'm no longer taking naps and SLEEP soundly throughout the night. Through nutrition tracking, I've been able to identify foods that trigger negative responses. I'm more conscious of labels and have started to truly enjoy expanding my diet. By treating other areas, my DIGESTIVE issues have dramatically IMPROVED.

Heidi F

I started coming to Dr. Voortmann this past March. For the most part, I consider myself a healthy individual that very rarely goes to the doctor except for my yearly physical. Each year my complaint is the same – I am tired. I have been sleep deprived for the past 20+ years living in a state of exhaustion. Waking up several times during the night & ending up in the recliner has been an every night occurrence for that long. Mornings would find me feeling sluggish, sore and my body would pop like a bowl of Rice Crispy’s on my way downstairs. After checking labs and all the usual things, my health provider would have no answers for me. I am not a fan of taking any medication so taking a sleeping aide was not an option. I was told that since I don’t drink pop, coffee or other caffeinated beverages, a pop or two a day might help give me a boost. That was not okay. All that did was make me feel bloated, gassy & didn’t do anything for my energy level. Upon coming to Dr. Voortmann and doing Nutrition Response Testing, I have started on natural supplements that are geared to give my body what it needs & has been lacking as well as getting rid of toxins. Keeping a food diary & going over it was something that Dr. Voortmann did with me that no medical provider ever took the time to do. Taking in her suggestions & kicking the pop out the door has been helpful. Over the past couple of months, I have started to notice changes and feel different. I feel like my body is slowly rejuvenating little by little. I am actually sleeping soundly through the night 3-4 nights a week now which is HUGE for me. It has made such a difference in my mental clarity & my morning stiffness is so much better! Although my results aren’t instant, I know that I am on my way to a healthier me. I didn’t just get this way overnight, so I know it won’t be a quick fix. I am confident that if you keep an open mind, committ and give Nutrition Response Testing a chance, it WILL make a difference for you like it has for me. ~ I am now starting Nutrition Response Testing with my 9 year old daughter in hopes of getting my whole family on board!

-Joan J. 

It’s been a little over a year ago that I started Nutrition Response Testing with Dr. Voortmann.  Although modern medicine does have its place, I’ve always believed in alternative forms of healing before taking any sort of prescription. Medication tends to alleviate the systems but does not cure the problem.  In my opinion, medications come with more risks & side effects that can cause more serious problems than what you started out with.  I came to Dr. Voortmann with sleep deprivation as my main issue wanting to find a safe way to address that.  This past year she has helped my body get the nutrients it needed and “peel” some of the layers that were causing me unrest.  I now have successful nights of rest where I actually get into a very deep sleep which was something that I rarely experienced in twenty years. 

Along the way when different things came up, Dr. Voortmann was able to use Nutrition Response Testing to understand what was going on within my body.    Recently I had been experiencing excruciating headaches which I attributed to needing new glasses.  Although my prescription changed, the headaches didn’t go away with new lenses.   Upon mentioning this to Dr. Voortmann at a maintenance visit, she evaluated me and determined that it was my kidneys having bacterial issues that were causing the pressure in my eyes.  After 1 day on supplements my headaches lessened and within 3 days they were gone.

Even as a believer in alternative medicine, I admit there were times that it was hard for me to wrap my brain around Nutrition Response Testing and how it all works.  It’s been a journey of discovery this past year learning that when you listen to your body, Nutrition Response Testing can help you discover what it is going on & what it is lacking.  It’s amazing when you start to see the connection yourself.   Going into this over a year ago, I knew that it would take time, an open mind and putting my trust in Dr. Voortmann.  It’s a commitment I am glad I made because I am in a much better place physically than what I was a year ago!

Joan J

Every now and then I come in with a new health issue, ache or pain just to keep Dr. Voortmann on her toes. She always figures it out on how to “fix it”

-Mary G.

Hi Dr. Voortmann. Wanted to leave a message to let you know that I am almost feeling back to normal. The last couple of months have been miserable and I feel like today I am almost 100%. It started about the 3rd day. I cut out all wheat, honey and sugar. I am sleeping better, exercising, skin is better, have more energy, and I feel better. See you at my next visit and I am going to keep it.

-Daphne S. (Phone Message)

I started the Nutrition with Dr. V 3 years ago. Before this I had frequent colds, flus, bronchitis, and pneumonia. I haven’t had the flu, bronchitis, or pneumonia in the past 3 years and only a few mild colds. I haven’t got the flu shots. My complaints of aches and pains have diminished. I have also been more aware of eating healthier. As a result of Dr. V’s educating me, I have more energy, am more mentally alert (most of the time) am happier and healthier.

-Mary G.

I was constantly tired, fatigued, and depressed. I am energized, happy, and have a general sense of well being. My body feels like it likes itself. I rarely get sick anymore and I sleep better. Karen T. I was constantly……. tired, fatigued, and depressed. Now I am energized, happy and have a general sense of well being. My body feels like it likes itself. I rarely get sick anymore and I sleep better.

-Karen T.

I suffered from IBS, bloating, indigestion, and constipation for about 2 ½ years. I went to Mayo Clinic and had several tests run and was told I had dumping syndrome. There are no pills for this condition. So I just watched what I ate. 1 week on the supplements and taking wheat and gluten out of my diet, I now can eat and not have bloating, indigestion, and constipation problems. I also have more energy and sleep better at night!


Before I started the nutrition program, stress controlled my life. My heart would race and I became very moody and always had a headache. Now my husband says that he is so happy that I am on the nutrition response program. He says that I am a lot happier and he is amazed how well I can handle stress now.

-Kristi Boston

I haven’t felt this good in 30 years! I am proof that it works!

-Linda B

Since I have been doing the Nutrition Response Testing Program, I can say that I haven’t felt this good in 30 years. I truly believe I have found the program that is going to make me well. I feel fantastic, I have more energy, more motivation, mind is not in a fog, and I can actually say without a doubt that my heart is much stronger. I am proof that it works!

-Linda B

“Before I came into Dr. Voortmann, I had high blood sugars due to type I diabetes, chronic fatigue, brain fog, intense sugar cravings and many other conditions that overwhelmed me and my health. Several weeks later after treatment my sugar cravings have gone down and my sugar levels have gone down 18 points and stabilized! I have more energy to keep up with my toddler daughter and I’m looking forward to my health improving even more! I have already seen improvements just in the last week”, she concluded.

-Jennifer Walrod “

I use to feel tired, lethargic, and hungry all the time! Now I don’t feel hungry all the time, and find myself busier due to that I not sleeping!!!


I was so tired. I did not have energy. Now I feel more energy. I can now do my favorite work out! I’m so happy now.

-F. A.

My daughter was diagnosed with ADD 2 years ago. Her father and I really struggled on the idea of giving her a “magic pill” to control her ADD symptoms. We tried to do everything from extra help & tutoring to keep her off of the medications. Finally the principal sat us down & explained to us that our daughter was struggling and we needed to go with the concerta her doctor had prescribed. She was put on a high dose of the medication. While being on the medicine she did do better at school but she also had a “zombie” type appearance and lost her personality. After talking to Dr. Voortmann about how unhappy I was about putting my daughter on the concerta. We explored the different routes we could take with the Nutrition Response Testing program. Since my daughter has been on the Nutrition Response Testing, her mental focus has improved dramatically and she has gone down to the lowest dose available on the concerta. It has been an amazing transformation!

-Shauna Hakes

Restless legs kept me up at night. I could only ride in a car for two hours. The legs were just annoying, I couldn’'t sit still, kind of hurt, but really just annoying. I had to take Advil to go to a three hour movie before legs started acting up around 9:30 pm every night. Exercise and Advil helped sometimes. Now I can sleep comfortably most of the time. If I forget minerals my legs tell me so. I can sit on the floor and I get up easier now.

-Dawn Theilen

I am pregnant and was suffering from nausea and vomiting and low energy. After 10 days - I haven’t vomited in 3 days, my nausea has improved a lot and my energy level is increasing.

-Cathy McMahon

I used to have VERY bad cramping with my menses for 2-3 days, which would result in me missing at least one day of school. After getting on the Nutrition Response Testing program my menses have drastically improved. I have very minimal cramping for only the first day of my menses and I no longer miss any school.

-4/13/11 RO

Before I started the nutrition program, stress controlled my life. My heart would race and I became very moody and always had a headache. Now my husband says that he is so happy that I am on the nutrition response program. He says that I am a lot happier and he is amazed how well I can handle stress now.

-Kristi Boston

In 2010, I was diagnosed with osteopena. I have been on supplements with Dr. Voortmann since 2010. In Feb. 2014, a repeat bone density test shows that my “bone mass density” is stable when compared to the previous examination.

Thank You Dr. V!

Hi Just had to report that I had a FANTASTIC day, feeling the greatest ever! Not this desire to EAT everything I see, NO desire or want to feeling at all today, WOW what a GREAT feeling, what a GREAT day! Wondering why I can not have these days every day! I desire to have many many more days like this...also, had my hair cut yesterday, my hairdresser is amazed how thick those new dark hairs are coming in and there seems to be more and more each time, yippy! She is wondering will all my white hair turn back to my dark brown or maybe just be a salt and pepper look, and how long might this take to make a complete change? She is in awe of this process, as I am too! Today just encourages me that I will get to my pot of gold, losing weight and being this healthy person. I thank God for you and what you have done for me. See you Thursday!

Abundant Blessings

-Linda B

Another Nutrition Response Testing doctor’s testimonial One is a gentleman who was told after a heart catheter that the back side of his heart was dead. He was told to go home and pack a bag. They were going to put him on an artificial heart device at Vanderbilt University until he could get a donor heart. At the behest of his wife, whom we had previously helped with a heart issue, he came directly to the office. We found a viral immune challenge and that he need Cyruta Plus and Antronex, Cataplex E2 and Cataplex G. He’s doing great and his cardiologist is baffled. Another fellow, age 56, had had a heart attack and was immediately stinted. He was told that he had two more arteries needing stints, one 80% and another 90% blocked. Six weeks later he went for the stints. They inserted the cath and much to their surprise he was less than 10% blocked and had to back out. This all took place because of Nutrition Response Testing, as I had him eating eggs and meat in the morning, etc. Once again the cardiologist couldn't understand. Fourteen months ago (Nov 2012), I had an increase in both my bi-focal and tri-focal prescriptions for my glasses. I had been having trouble reading. Last week (Jan 2014), my eye exam showed an IMPROVEMENT OF +.25 in my left eye on both the bi-focal and tri-focal.

-Mary G. Nutrtion Response Test Patient

My 15 year old daughter had a bad reaction to the gardicil shot. She had numbness and tingling in arms and legs, fatigue and brain fog with and inability to concentrate and retain information. Her grades were dropping and she became very emotional. After coming to Dr. Voortmann, we began detoxing and treatments. Within 3 weeks I started seeing a difference. Now in less than 2 months, she has more energy, enjoys studying again and grades are going up. She no longer has numbness or tingling in her arms and legs. So thankful for Dr. Voortmann. She helped me get my daughter’s life back!

-TSP Clear Lake

Like so many other people, I just wasn’t feeling the way I felt I should. I tried adjusting some things on my own, but didn’t get the desired results. 

I saw an advertisement for Dr. Voortmann and decided to spend some money on my health. AM I GLAD I DID! Within several days of some new supplements, a couple of chiropractic treatments, and changes to my diet, I began feeling noticeably better. My mind was clearer, I felt better after the 1st month than I had in a few years.

Now I’m in the end of my 2nd month. I have lost 12 pounds for the 20 I want to lose. I feel more alert, sleep less, and overall feel better.

As a big bonus my seasonal allergies have been about 80% better too!

Thank you Voortmann Clinic Bob S.

I woke up from my sleep one night, violently ill and couldn't hardly get out of bed. I called into work that day and felt miserable all day. The next day I came to see Dr. V and she gave me some supplements that I could drink through out the day. She assured me that I would feel better. She couldn't have been more right, I took the supplements in some water, went home took a three hour nap, and was back to work that afternoon. There's no telling how long I would have been out of work if it hadn't been for Dr. V. So thankful!

Melissa D.

Thought of the day:

One huge thing about Nutrition Response Testing is, the practitioner does testing to find problem areas on you. Sometimes you don’t know they are a problem, sometimes you think it’s something else, but with an MD it’s completely different. Most of the time we have a noticeable problem, before the MD helps us with it. Myself I didn’t know I had a bad gall bladder until it was too late, I was told I was having indigestion issues and not even 3 months later, had to have emergency gall bladder removal surgery. Isn’t it better to be proactive rather than reactive with your health? MJ- NRT Patient

I am extremely impressed with Natural Response Testing. Since being introduced to it by Dr. Voortmann over a year ago, I have learned how so many health problems can be remedied by using an all-natural approach to correcting the exact problem areas of the body. I spent a whole summer going to doctors trying to figure out why I was unusually tired, not feeling well overall and had a rash that was not going away. I was given various medications that didn’t help, andeven had a skin biopsy that also did not result in pinpointing the problem. I was so frustrated and miserable, until someone I knew recommended that I make an appointment with Dr. Voortmann. Through the Nutrition Response Testing, Dr. Voortmann, determined what was going on with my organs and immune system, and put me on the determined supplements. Within weeks, I began feeling better and my rash was gone. I have continued seeing her every 6 weeks to keep checking the progress of how the supplements are working with my body as a whole, as well as checking any additional concerns that I may come up. NRT just makes so much sense. Dr. Voortmann is wonderful to work with, and I so appreciate what she has done to help me improve my overall health. 

Mary Wendt, Mason City