The Deal on Vitamin D

The Deal on D

Hello, people! Last week, we finished our series on personality disorders. Now that everyone has “properly diagnosed” their coworkers, friends, neighbors, and family, we’ll be having a quickie two part piece on vitamin D before starting a new series. 

Chances are, your parental units always told you “Drink your milk!” Why? Because it contains vitamin D, which is essential, along with calcium, to maintain healthy bones and teeth, just like they said… but vitamin D does a whole lot more than that. More on that in a few. First, let’s talk about what it is. 

Adolf Windausin was awarded the Nobel Prize in 1928 for his role in the discovery of vitamin D. Everyone thank Adolf… Thanks for that Adolf, good job! But despite its name, vitamin D isn’t actually a vitamin, it’s really a neuroactive steroid. It’s a hormone, just like testosterone, estrogen, corticosteroids, and our thyroid hormone friends we talked about in a series several weeks ago. Vitamin D is required to absorb and metabolize calcium, but it’s about more than just bones and teeth. Almost every cell in your body has a receptor for vitamin D, and it’s essential to many processes. Vitamin D is a transcriptional regulator for a large number of genes important for brain function, meaning it influences their expression, and is required for normal brain development. It’s involved in homeostasis, and it regulates melatonin production, the hormone involved in the human circadian rhythm and sleep patterns. It supports good lung function and cardiovascular health, and is involved in regulating insulin levels. And it happens to be responsible for stimulation of the most important antioxidant in the brain, the neuroprotectant glutathione, or GSH. Antioxidants like GSH help to counteract free radicals, the nasties that contribute to aging and some diseases, possibly even cancer. As it increases GSH production, vitamin D helps protect the body from their damaging effects.

Generally speaking, vitamins are nutrients that the body cannot create on its own, so a person must consume them in their diet, or boost intake through supplements. However, vitamin D is a little unusual, in that the body can produce it as a response to sun exposure… as long as you’re not wearing sunscreen or are covered by clothing head to toe, mind you. Sensible sun exposure on bare skin for 5 to 10 minutes, two or three times per week, allows most healthy people to produce sufficient amounts of vitamin D. Even though it’s easy to get a dose of D, many healthy people are D-ficient ha ha. Depending on the reference, anywhere from between 42 and 64 percent of the American adult population has low levels, but hypovitaminosis D has been shown to be even more common among older adults, with some references indicating it affects up to 90 percent of the elderly population. Deficiency is fairly common across the board, but is of special concern in pregnant women, as the fetus relies completely on maternal stores. More on the potential effects during pregnancy will be discussed in a moment. Studies have demonstrated that deficiencies play a role in a wide range of diseases and disorders, including autoimmune/ inflammatory, cardiovascular, neuropsychiatric, and more. Supplemental vitamin D has been shown to be beneficial as part of a treatment regimen for some of these conditions. On that note, I should mention that two forms of vitamin D exist, D2 and D3. D3, or cholecalciferol, is the more powerful of the two types, and this is the supplemental form that’s naturally present in the human body.

Where and How Much?

Getting sufficient sunlight is the best way to help the body produce enough vitamin D. Otherwise, it’s always best to get nutrients from natural dietary sources, but good D3 supplements are inexpensive, and that may be the way to go if levels are low. Plentiful food sources of vitamin D include fatty fish, such as salmon, mackerel, and tuna; egg yolks, cheese, beef liver, mushrooms, fortified milk, and fortified cereals and juices. How much vitamin D you need depends on many factors, including age, ethnicity, latitude, season, and amount of sun exposure. Dosage is measured in micrograms (mcg) or international units (IU). One microgram of vitamin D is equal to 40 IU. The National Institutes of Health (NIH) recommends an average daily intake of 400 – 800 IU, or 10 – 20 micrograms, but some studies indicate that the daily intake needs to be higher if you’re a couch potato, aren’t exposed to the sun, or have darker skin tones. Please note that everyone processes and absorbs substances differently, and your levels can be checked in an annual physical, or sooner if you suspect you’re low. Home test kits are undoubtedly available on the interwebs. Don’t forget the kids when it comes to supplements. Children younger than 12 months old need 400 IU each day, while children 12 to 24 months old need 600 IU. Drops are available for ease of dosing.

Depending on who you ask, blood levels above 20 ng/ml or 30 ng/ml are considered as “sufficient.” One study of healthy adults showed that a daily intake of 1,120 – 1,680 IU was needed to maintain sufficient blood levels, but the same study showed that deficient individuals needed 5,000 IU each day to reach the same level. It’s all relative, people. Studies in postmenopausal women with vitamin D levels below 20 ng/ml found that ingesting 800 – 2,000 IU raised blood levels above 20 ng/ml. However, proportionally higher doses were needed to reach the 30 ng/ml level. People who are overweight or have obesity may also require higher amounts. All things considered, a daily vitamin D intake of 1,000 – 4,000 IU, or 25 – 100 micrograms, should be enough to ensure optimal blood levels in most people. 

For people with vitamin D deficiency, it may be appropriate to use up to 50,000 IUs weekly for up to three months, or until levels become normal, and then switch to a maintenance dose, usually between 2,000 and 5,000 IU daily. But Captain Obvious says that needs to be documented and handled by a physician. If you don’t have a deficiency and you take that much, you might be sorry. According to the NIH, the safe upper limit is 4,000 IU. Make sure not to take more than that without consulting with a healthcare professional. Excessive consumption of vitamin D supplements can lead to over calcification of bones, and the hardening of blood vessels, as well as kidney, lung, and heart tissues. The most common symptoms of excessive vitamin D include headache and nausea, but it can also cause loss of appetite, dry mouth, a metallic taste, constipation, and diarrhea. 

D-ficiency

Although the body can create vitamin D, a deficiency can occur for many reasons. Darker skin, sunscreen use, and the time of year reduce the body’s ability to absorb the ultraviolet radiation B (UVB) rays from the sun, and this is critical to produce vitamin D. Deficiency during pregnancy is especially concerning, as it may lead to a greater risk of mom developing gestational diabetes, preeclampsia, and having preterm birth. 

Recent evidence in clinical literature suggests that the development of autism spectrum disorders may be attributable to maternal vitamin D deficiency. In addition, vitamin D is a critical contributor to immune function during pregnancy, and the placenta contains the considerable amount necessary for fetal development. Vitamin D deficiency can also increase risks of inflammatory and infectious diseases given its role in innate and autoimmunity. There are receptors for vitamin D throughout the entire central nervous system and in the hippocampus of the brain. It activates and deactivates enzymes that are involved in neurotransmitter synthesis and nerve growth. Studies suggest it protects neurons and reduces inflammation, and deficiency is associated with several medical conditions, including Alzheimer’s disease, dementia, Parkinson’s disease, autism, OCD, sleep impairment, infectious/ inflammatory diseases, and autoimmune disorders such as diabetes and rheumatoid arthritis. Symptoms of vitamin D deficiency may include regular sickness or infection, fatigue, bone and back pain, low mood, impaired wound healing, hair loss, and muscle pain. If vitamin D deficiency continues for long periods of time, it may result in serious illness, including cardiovascular conditions, autoimmune problems, neurological diseases, infections, pregnancy complications, and certain cancers, especially breast, prostate, and colon.

Illnesses Linked to D-ficiency

Skeletal/ Bone Health Issues

Vitamin D deficiency in children can cause rickets, a disease which leads to a severely bowlegged appearance due to the softening of the bones. In adults, vitamin D deficiency manifests as osteomalacia, or softening of the bones, a condition that results in poor bone density and muscular weakness. One of vitamin D’s primary roles is to maintain skeletal health through a synergy with calcium, and low levels of vitamin D decrease calcium absorption, lead to low bone calcium stores, and increase the risk of fractures. Ultimately, vitamin D deficiency can lead to osteoporosis, which over 53 million people in the United States either seek treatment or face an increased risk for. Osteoporosis occurs when new bone doesn’t generate at the same pace as the loss of old bone, it’s lost faster than it can be replaced. Bones then become brittle and more prone to fracture.

Neuropsychiatric Disorders 

Over the past several years, vitamin D deficiency has been associated with an increased risk of brain-related disorders. Vitamin D alters cholinergic, dopaminergic, and noradrenergic neurotransmitters systems, and abnormalities in these neurotransmitters have been implicated in various neuropsychiatric diseases. These include schizophrenia, autism, depression, Parkinson’s disease, dementia/ Alzheimer’s disease, and, most compellingly, multiple sclerosis, MS. As I mentioned in the intro, depending on what reference you believe, a large percentage of people fall short of the 30 ng/mL sufficient threshold of vitamin D, but these numbers skyrocket among people with brain disorders. An estimated 80 percent of people with multiple sclerosis (MS) and 90 percent of people with dementia have vitamin D levels of less than 20 ng/mL. Researchers suspect that people with Parkinson’s or Alzheimer’s disease and the elderly are similarly deficient. Why are the aged so deficient? Aging reduces skin thickness, which inhibits the body’s ability to make vitamin D from sun exposure. When this is coupled with reduced dietary intake of vitamin D and the impaired intestinal absorption that also accompanies aging, deficiency is almost inevitable. More research is needed to elucidate the mechanisms involved, the how and why. Unfortunately, a simple vitamin D supplement isn’t the answer to these neurodegenerative diseases. Someday we’ll get it figured out. 

Next week, I’ll continue with illnesses of D-ficiency. 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