Vitamin D Part Two

Hello people… hope everyone had a great weekend! This week, I’m going to finish up our discussion on the big D… vitamin D! Last week, we talked about how it’s not actually a vitamin, it’s really a hormone. And unlike most vitamins, it can be synthesized in the body, provided there’s sufficient skin exposure to the sun- it doesn’t take much- maybe 10 minutes two or three times a week. If you spend all your time inside, have very dark skin, or constantly wear high spf sunscreen, you may need to take a vitamin D supplement. Maintaining adequate vitamin D is essential for many basic processes, far beyond the bones and teeth. Vitamin D helps the immune, muscle, and nervous systems function properly, and a surprising percentage of the population are chronically low. Last week, I mentioned that the elderly population are especially at risk of severe D-ficiency, and this increases the risk of several brain-related disorders. Vitamin D alters cholinergic, dopaminergic, and noradrenergic neurotransmitters systems, and abnormalities in these neurotransmitters have been implicated in various neuropsych diseases and disorders, such as schizophrenia, depression, Parkinson’s disease, dementia/ Alzheimer’s disease, and multiple sclerosis, MS. This week, I’ll finish discussing what researchers know about vitamin D deficiency and these disorders thus far. 

Dementia

A 2014 study found that moderate and severe vitamin D deficiency in older adults was associated with increased risk for some forms of dementia, including Alzheimer’s disease. Dementia involves a decline in thinking, behavior, and memory that negatively affects daily life. Alzheimer’s disease is a neurodegenerative disorder and the most common form of dementia, accounting for as many as 80 percent of dementia cases. When compared with people who had normal vitamin D levels, the study found that people with low levels of vitamin D had a 53 percent increased risk of developing all-cause dementia, while those who were severely deficient had a 125 percent increased risk. In addition, people who had lower levels of vitamin D were about 70 percent more likely to develop Alzheimer’s disease specifically, and those who were severely deficient were over 120 percent more likely to develop it. These findings may seem alarming, especially considering the devastating toll that dementia can have on patients and their families, but don’t panic- this was an observational study, meaning it cannot prove a direct cause-and-effect relationship between vitamin D deficiency and dementia and Alzheimer’s. You have to consider that the risk of both Alzheimer’s and dementia already increase with advancing age, and vitamin D deficiency increases with advancing age, so you have to wonder if the relationship is incidental, or if there’s a causal mechanism at play. Researchers are trying to tease out the findings to answer that. Nonetheless, the theory is that the “sunshine vitamin” might help literally clear the patient’s heads- the vitamin D may protect against dementia by helping to break down and sweep out the protein plaques commonly linked to dementia and Alzheimer’s disease. This would increase blood flow to the brain as well, which is a good thing. 

Multiple Sclerosis

Vitamin D receptors are present throughout the central nervous system, and research has shown that maintaining adequate levels of vitamin D can have a neuroprotective effect. When a person has multiple sclerosis, MS, the immune system attacks the myelin coating that protects the nerve cells, damaging them and affecting transmission of signals. But studies show that vitamin D may lower the risk of developing MS. A number of studies have shown that people who get more sun exposure and vitamin D in their diet have a lower risk of MS, so vitamin D levels are considered to be an important modifiable environmental risk factor for development of the disease. For people who already have MS, some studies suggest that vitamin D may offer some benefits- it may lessen the frequency and severity of their symptoms, which improves quality of life, and lengthens the time it takes to progress from relapsing-remitting multiple sclerosis to the secondary-progressive phase. At this point, the evidence isn’t conclusive, more research is needed, but the connection between vitamin D and MS is strengthened by the association between sunlight and the risk of MS. Studies have shown that the farther away from the equator a person lives, the higher the risk of MS. This suggests that exposure to sunlight may offer protection from MS. Therefore, researchers theorized the link to vitamin D and set out to explain it.

A team of Harvard researchers conducted a study and reported that women who ingested more vitamin D from food (approximately 700 IU/day) had a 41 percent lower risk of MS as compared to women with lower intakes; those who took vitamin D supplements (400 IU/day or more) had a 33 percent reduced risk of developing the disease, as compared to those who did not. In another Harvard study, researchers discovered that some people, specifically caucasians whose blood levels of vitamin D were above 40 ng/mL (meaning levels were sufficient) had a 62 percent lower risk of developing MS. More recently, researchers have linked higher blood levels of vitamin D with reduced risk of relapse, less active lesions on MRI, and possible neuroprotective effects. Although it’s not clear what role vitamin D plays in MS, hypotheses involve its impact on the immune system, and question potentially faulty vitamin D receptors in people with MS.

Parkinson’s, Preliminary Association

Most evidence on the link between vitamin D and Parkinson’s disease (PD) has been from animal studies, but human trials have also uncovered a potential connection between chronically deficient levels of vitamin D and the development of PD. A Finnish follow up review of 3,173 men and women without PD found that those with higher blood levels of vitamin D showed a reduced risk of the disease. An Emory University publication found that more people with PD, 55 percent, had a vitamin D deficiency than a control group, 36 percent. Scientists still don’t know how exactly vitamin D levels affect Parkinson’s risk, but the findings are generating interest in more research. 

Depression

Most people are familiar with seasonal affective disorder (SAD), which happens during seasons with less light exposure. The relationship between sunlight and depression is no accident, so it’s no surprise that vitamin D deficiency may be linked to a higher risk of depression. After all, the nickname for vitamin D is the sunshine vitamin, and that’s not just because many people generate much of their required amount thanks to sun exposure. Vitamin D status is also connected to a sunny, or not so sunny mood. Research has previously demonstrated a relationship between low mood and low vitamin D levels, and in fact, I see many patients with depression that have low vitamin D levels. The two seem to go hand in hand, which is why this is an important topic. A study I read not long ago utilizing high dose vitamin D found that participants had a significant decrease in depression and anxiety, and an improvement in general mood. I’ve found vitamin D supplementation to be very helpful in patients with mood disorders, even treatment resistant depression, especially in those who also have other inflammatory-related conditions. I have one patient that just started a D3-K2 supplement I suggested that also has rheumatoid arthritis, and I’m hoping it will improve symptoms of both. K2 is menaquinone, a micronutrient supplement that works synergistically with D3. I’ll talk about it in a moment.

Risk of Schizophrenia

Schizophrenia is a severe brain disorder that affects less than one percent of American adults. Symptoms commonly appear between ages 16 and 30, and include delusions, hallucinations, incoherent speech, withdrawal from others, and trouble focusing or paying attention. A scientific review from 19 observational studies suggests that people who are vitamin D deficient may be twice as likely to be diagnosed with schizophrenia, as compared with people with sufficient vitamin D levels. Schizophrenia is more prevalent in places with high latitudes and cold climates, and studies suggest children who relocate to colder climates appear to be at a higher risk of developing it. While the researchers observed a link between the two factors, I should note that we need some randomized controlled trials to better define the link and to determine if supplementation may help prevent it. Probably couldn’t hurt. Considering what we know about the role of vitamin D in mental health, the findings seem to have merit.

Diabetes mellitus 

Vitamin D deficiency has been implicated in the pathogenesis of multiple autoimmune diseases, including diabetes mellitus type 1.

The connection seems clear, but why it exists is not. Some researchers believe the link is related to the role of vitamin D in insulin sensitivity and resistance, which results in increasing blood sugar. The hormone insulin helps control the amount of sugar, or glucose in the blood. With insulin resistance, the body’s cells don’t respond normally to insulin, and glucose can’t enter the cells as easily, so it builds up in the blood. So you have high blood glucose levels, and this can eventually lead to type 2 diabetes. Researchers theorized that low vitamin D levels change glucose “homeostasis,” which just means it affects how you maintain a proper level. Studies have found that when vitamin D is deficient, many cellular processes in the body begin to break down, and this may be what sets the stage for the onset of diseases like diabetes. In animal studies, vitamin D deficiency has been shown to have a detrimental effect on insulin synthesis and secretion, and some human observational trials have also indicated a correlation between pre-diabetic states and vitamin D levels. But in the randomized controlled trial on vitamin D in pre-diabetic states, not all the evidence supported that increasing vitamin D levels through supplementation results in improvements in insulin sensitivity. In some cases, it didn’t improve. So the jury’s out as far as proof of the influence of vitamin D on glucose homeostasis. Most of the data suggests it’s helpful, but we don’t have a definitive answer as yet.  

Rhematoid Arthritis, RA

Vitamin D has been found to have immunomodulatory actions, meaning it may help keep the immune system in balance. Autoimmune diseases like RA occur when the affected person’s immune system attacks their own tissues, hence the name. It’s been previously established that reduced vitamin D intake has been linked to increased susceptibility to the development of RA. Deficiency has also been found to be associated with disease severity in patients with RA; low vitamin D can lead to more severe disease. As I mentioned last week, vitamin D deficiency can cause bone loss and diffuse musculoskeletal pain, similar to that which occurs in RA. Science is always looking at common links to exploit them therapeutically. They also knew that vitamin D supplementation may help prevent osteoporosis, so they put that all together and theorized that vitamin D may also help decrease pain associated with flares of RA. “Flares” are periods of time when the disease is active, when the person’s immune system is attacking their bones and joints, and they can be extremely painful. So they started looking at vitamin D and RA disease states. Researchers of one large study found that only 33 percent of the people with RA they studied showed satisfactory vitamin D levels- 77 percent were low. And the people who had active RA at the time, who were experiencing more severe symptoms, their vitamin D levels were even lower. While the link between vitamin D and RA is well known, this was the first study to look at the impact of levels on the course of established disease. So those of you at risk of RA or with constantly flaring RA, make sure to get your D checked!  

Prostate Cancer

A published 2014 study found a link between low blood levels of vitamin D and aggressive prostate cancer in European American and African American men. Researchers looked at vitamin D levels in 667 men, ages 40 to 79, who were undergoing prostate biopsies. The connection between low vitamin D and prostate cancer seemed especially strong in African American men. The results suggested that African American men with low vitamin D levels were more likely to test positive for cancer than men with normal vitamin D levels. These findings were observational- meaning that they didn’t prove that low vitamin D led to prostate cancer, just that the two factors may be linked- it does suggest you may reduce your risk by ensuring adequate vitamin D levels. Captain Obvious says you should also make regular doctor’s visits, and watch for common prostate cancer symptoms, to make sure you get an early diagnosis and treatment if you’re affected. Common symptoms are difficulty starting and maintaining a steady stream of urine, frequent urination, excessive urination at night, urge to urinate, and/ or weak urinary stream. Prostate cancer occurs mostly in older men, and the average age of diagnosis is about 66 years of age. Other than skin cancer, it’s the most common cancer in men, and the second most common cause of cancer death in American men, per the American Cancer Society. Just a friendly PSA from MGA.

Severe Erectile Dysfunction, ED

A small 2014 study of 143 subjects found that men with severe ED had significantly lower vitamin D levels than men with mild ED. The researchers theorized that vitamin D deficiency may contribute to ED by impeding the arteries’ ability to dilate, another “ED” condition called endothelial dysfunction. Captain Obvious says that one of the requirements for achieving an erection is proper function of the arteries, as they’re responsible for supplying the penis with blood so it can become engorged. Ironically, arterial stiffness may be the cause of the endothelial dysfunction that causes the erectile dysfunction… basically, if the arteries are too stiff to dilate, something else won’t be. And in fact, a totally separate study suggested that a lack of vitamin D was indeed linked with general arterial stiffness in healthy people. Another PSA: ED is the most common sexual complication among men, and according to the National Institute of Diabetes and Digestive and Kidney Diseases, it affects up to 30 million American men. It can stem from other health conditions, including diabetes, prostate cancer, and high blood pressure. Common ED treatments include hormone replacement therapy, counseling, and lifestyle changes like quitting smoking, limiting alcohol, and eating a balanced diet. Yet another reason to check your D.

Breast Cancer

It’s not just prostate cancer that shares a link with low vitamin D levels, there’s also a link between vitamin D deficiency and breast cancer. A 2017 published review found that “most” vitamin D studies support the “inverse association” between vitamin D level and breast cancer risk. That’s nerd speak for saying that women with low levels of vitamin D have a higher risk of developing breast cancer. A 2019 in vitro study, meaning “in glass” in a lab, found that high concentrations of vitamin D inhibited breast cancer cell growth. In addition, studies and statistics indicate that women with breast cancer that have adequate or high vitamin D levels seem to have better outcomes- fewer cases of metastases, fewer deaths. So it appears that vitamin D may play a role in controlling breast cell growth, and that high levels may be able to actually slow or halt growth. It’s exciting stuff, but cells isolated in a petri dish in a lab are one thing, and cells in a walking talking human with all of the additional influences are quite another, so human trials are needed before we celebrate with a giant vitamin D cake. But it’s a start. The American Cancer Society estimates that in 2021, 281,550 new cases of invasive breast cancer will be diagnosed in women, not including about 49,290 new cases of ductal carcinoma in situ (DCIS) and about 43,600 women will die from breast cancer. Horrible.

D3’s BFF, K2

This isn’t a math formula, this is a quick note on vitamin K, a micronutrient that most people haven’t ever heard of. K vitamins are critical cofactors for a variety of proteins in the body, including factors involved in blood clotting, calcium transport, insulin regulation, fat deposition, cell proliferation, and DNA transcription. Vitamin K comes in many different forms, traditionally divided into two groups. Vitamin K1, aka phylloquinone, is the most common form of vitamin K. It’s found in plants, notably leafy greens like kale, spinach, turnip greens, collards, Swiss chard, mustard greens, parsley, romaine, and green leaf lettuce. Vitamin K2, aka menaquinone, is mainly found in fermented foods like natto, miso, and sauerkraut. Because K2 is found in so few foods, it’s most commonly found in supplement form. K2 is D3’s BFF. They work synergistically, so current prevailing wisdom says you should take them together. While vitamin D3 improves your calcium absorption, vitamin K2 allocates where that calcium can be used. It’s responsible for depositing the calcium at the right places in the body, like in the bones and teeth. It also prevents calcification, the accumulation of calcium in places where it is not required, like in the arteries and other soft tissues of the body. You definitely don’t want it there. Also, vitamin D needs calcium for metabolism, and when you aren’t getting enough calcium from your diet or from supplementation, vitamin D may pull the calcium it needs from your bones. That’s clearly not the best thing. Taking vitamin D stimulates the body to produce more of the vitamin K2-dependent proteins that transport calcium. These proteins have many health benefits, but can’t be activated if insufficient vitamin K2 is available, so anyone who’s taking vitamin D needs more vitamin K2. Deficiencies in both are extremely common, and more and more people are taking both D3 and K2 together as a daily dietary supplement. This raises the question of how they’re best combined. The current dietary guidelines don’t distinguish between vitamin K1 and K2. There are many D3-K2 combination supplements widely available. If for some reason you choose to take K2 but not D3, 45mcg of vitamin K2 a day is generally enough for healthy people under the age of 50, but again, this recommendation only applies if there is no additional vitamin D3 intake from dietary supplements. If you do take a D3 supplement, the recommended dosage is increased to 100mcg – 200mcg vitamin K2 per day. The higher dosage of 200mcg is recommended for people who have a history of cardiovascular disease or osteoporosis in their families. I recommend the combination product to my patients, as long as it’s not contraindicated. Please note: vitamin K helps your blood clot, so if you are taking anticoagulant medication like coumadin to prevent blood clots, please consult your doctor before taking it. Generally speaking, if you do take an anticoagulant, 45 mcg vitamin K2 per day is a safe dose, but talk to the physician who prescribes the anticoagulant first. 

So that’s the deal on vitamin D. The moral of the story is that the vitamin that’s not a vitamin is very busy in the body… it’s not just about the bones anymore. Having adequate levels of it may mean the difference between developing a debilitating disease one day and avoiding one, so make sure you get enough. Check your levels, and consider a supplement if you need it. And don’t forget its best friend K2. 

I hope you enjoyed this blog and found it to be interesting and educational. Please feel free to share it with family and friends. Be sure to check out my YouTube channel with all of my videos, and I’d appreciate it if you would like, subscribe, leave comments, and share those vids! As always, my book Tales from the Couch has more educational topics and patient stories, and is available in office and on Amazon. 

Thank you and be well people!

MGA