One of the most important supplements I take is Vitamin D. Ideally, we should be getting Vitamin D from the sun. Realistically, most of us are indoors all day and do not soak up nearly the amount of sun we need to make enough Vitamin D.
Why is Vitamin D so important?
Vitamin D is actually a misnomer, because it is not a vitamin, but, in fact, a fat-soluble steroid hormone obtained from sun exposure, the foods we eat, and supplementation.
A few of its vital roles include:
- absorption of calcium to promote strong bones and teeth
- regulation of the neuromuscular system for muscle control
- regulation of the immune system to fight infection
- support of the cardiovascular system for heart function and circulation
- support of the respiratory system for lung function
- aiding brain development
- anti-cancer effects
Recent studies have shown that Vitamin D deficiency has been linked to breast cancer, colon cancer, prostate cancer, heart disease, weight gain, and inflammation as well as Type 2 Diabetes and emotional disorders such as depression, dementia, and Alzheimer’s. It was found that people with higher levels of Vitamin D generally have a lower risk of these diseases. This is possibly because scientists have discovered about 3,000 genes that are controlled by the Vitamin D levels in our bodies.
How do I get Vitamin D and how is it metabolized in my body?
1) Sunlight is the best way to get Vitamin D. Your body can potentially produce 10,000 – 25,000 International Units (I.U.’s) of Vitamin D in half the time it takes your skin to turn pink or burn in the sun during mid-day (e.g., if it takes you 30 minutes in the sun to burn, expose your skin for 15 minutes). The most Vitamin D is produced when a large part of your skin is exposed to the sun (i.e., the skin on your back, rather than just your arms and legs).
Metabolically speaking, when UVB rays from the sun hit your skin, Vitamin D3 is produced and taken to the liver where it is changed to 25-hydroxyvitamin D3. 25-hydroxyvitamin D3 is then sent to your kidneys and transformed into its activated form or 1,25-hydroxyvitamin D3, the form that allows Vitamin D to carry out its various tasks.
2) Some foods that contain higher levels of Vitamin D include:
– Cod liver oil – 500 I.U.’s per teaspoon
– Fatty fish – 792 (eel), 645 (trout), and 307 (wild salmon) I.U.’s per 3 ounce serving
– Portobello and Maitake mushrooms – 384 I.U.’s per diced cup (86g)
– Cheese – 134 I.U.’s per cup (122g)
– Egg Yolks (hard-boiled) – 44 I.U.’s per egg
When you ingest Vitamin D supplements or foods containing Vitamin D, your gut will send Vitamin D3 to your liver and repeat the same reactions mentioned above.
3) Vitamin D3 supplements are necessary if you can’t get enough sun exposure or eat enough Vitamin D rich foods to produce sufficient amounts in your body.
Who is at risk for Vitamin D deficiency?
Risk factors for Vitamin D deficiency include:
- age > 50 – With age, our ability to convert sunlight into Vitamin D and our kidneys’ ability to convert Vitamin D into its usable form decreases.
- people with more melanin in their skin (darker skin) – If you have dark skin, you may need up to 10 times more sun exposure to produce the same amount of Vitamin D as someone with fair skin.
- obesity – Vitamin D is fat soluble and gets trapped in fatty tissue preventing metabolization in the body.
- people with malabsorption or gut problems – Any gastrointestinal issues that may affect your ability to absorb fat will also affect your ability to absorb Vitamin D (e.g., Crohn’s Disease, Whipple’s Disease, Cystic Fibrosis, Celiac Disease, any type of liver disease).
- sunscreen use and staying indoors – Using sunscreen blocks the UVB light needed in our skin to convert Vitamin D to its usable form. This is a dilemma as we also need sunscreen to protect against skin cancer from prolonged sun exposure.
- geographic latitude – People who live north of 35 degrees latitude receive less sunlight.
- use of certain medications – Anti-seizure medications, glucocorticoids (steroid medications), Rifampin (Tuberculosis medication), HIV medication, and St. John’s Wart have been found to affect Vitamin D metabolism.
What levels should my Vitamin D be at?
The old school of thought shows a wide “normal” range for Vitamin D levels from 30-100ng/ml. Extensive research has now shown that the optimum level should be between 40-60ng/ml. We will revisit how researchers have come up with this number in a later post.
How much Vitamin D do I need to take to reach optimum levels?
First, get your baseline Vitamin D levels checked. The test you want is a 25-hydroxyvitamin D or 25(OH) D test (remember, this is what is produced in your liver). If you are not deficient, you may only need 1000-2000 I.U.’s daily to maintain your levels. If you are deficient, (i.e. under 40ng/ml), the guidelines are as follows:
Age Under 5: 1000 units daily
Age 5-10: 2500 units daily
Adults: 5000-6000 units daily
Pregnant and Nursing Women: 5000-10000 units daily
In general, to achieve optimal levels, most adults and the geriatric population need to be taking between 5000-6000 I.U.’s of Vitamin D daily, especially during the winter months, and from all sources combined (sun, food, and supplements). Don’t worry about overdosing, as there have been no reported cases of Vitamin D toxicity below 10,000 I.U.’s of Vitamin D per day. As with anything, everyone responds differently to supplementation. Some people may require a smaller dose to reach optimal levels while others may require more. These are, of course, rough guidelines and the best way to determine how much you need is to recheck your levels at least once a year and adjust your dose accordingly.
What is the best form of Vitamin D to take and when should I take it?
Because it is a fat-soluble vitamin, the best form to take is liquid Vitamin D3 with your heaviest or fattiest meal of the day to maximize absorption. When I am pregnant or nursing, I take 6000 I.U.’s of Ortho Molecular Products Liquid Vitamin D3 daily. Otherwise, I take 5000 I.U.’s daily. For my son, I gave him Carlson Super Daily D3 drops for babies, 400 I.U.’s daily until he was 6 months old. Afterwards, I increased his dosage to 1000 I.U.’s daily using Ortho Molecular Product’s Vitamin D3. My most recent level (taken last summer) was 44ng/ml, while his level was 49 ng/ml. As you can see, taking 5000-6000 I.U.’s daily kept me just above the optimal level!
I hope you now have a better understanding of the basics of Vitamin D. Have a great weekend!
In health and wellness,