Happy Tuesday, everyone!
Today I’m bringing you the scoop on one of my favorite micronutrients Vitamin D, also known as the sunshine vitamin! This post could not be more perfect considering Milwaukee has a complete lack of sunlight lately with intense fog and now rain. It goes on for weeks and is a nice reminder to mind my vitamin D status because sun is harder to come by these days.
You may be blankly staring at the screen wondering why I don’t just take a supplement but I’m going to discuss today which form of Vitamin D is best for your body.
Facts you may not know about Vitamin D:
- Vitamin D is NOT calcium (you would be surprised how many people do not know this)
- Your body is able to create Vitamin D through your skin
- Vitamin D is able to raise calcium levels in your body
- Sunscreen is a possible culprit behind Vitamin D deficiency
- Vitamin D relies on fats to be absorbed
Let’s just start off with what Vitamin D is, shall we?
What is Vitamin D?
Vitamin D is a fat-soluble vitamin that is necessary for your body to maintain strong bones, strong muscles, and a healthy heart. Your body is able to synthesize Vitamin D through sun exposure, but lesser quality forms include fortified foods and supplements.
How do we create Vitamin D in our bodies?
Note: extremely nerdy explanation ahead!
7-dehydrocholesterol is a steroid in your skin and UV rays from the sun convert it to cholecalciferol, or Vitamin D3. D3 is absorbed into your blood stream and picked up by DBP, or Vitamin D binding proteins that deliver D3 to the liver. Once in the liver, D3 is hydroxylated and converted to 25-hydroxylase, or Calcidiol. Calcidiol is then diffused into the blood and absorbed by the kidneys to be hydroxylated by 1-hydroxylase to form 1,25-dihydroxycholecalciferol, or Calcitriol. Calcitriol is the most active form of Vitamin D and is ready for use in your body.
UV rays from the sun create an inactive form of Vitamin D in your skin which is absorbed from your skin into your blood stream and then sent to your liver. The liver sends it to your kidneys where the active form of vitamin D will be formed.
What is the relationship between Vitamin D and Calcium?
(please don’t let this be you, haha)
Note: extremely nerdy explanation ahead!
When calcium levels are low, parathyroid hormone is released and calcitriol synthesis begins in the kidneys, which as you just learned above is the active form of Vitamin D that your body uses. When calcium levels are too high, also known as hypercalcemia, the hydroxylation of D3 is halted and no calcidiol is hydroxylated into calcitriol, the active form.
When calcium levels are low your body produces or uses the active form of Vitamin D. Vice versa, if calcium levels are too high your body does not produce or use the active form of Vitamin D
What is the best way to consume Vitamin D if I can’t get sun exposure?
Acceptable Dietary Sources of Vitamin D –
It is a misconception that a healthy diet involves vitamin D and that foods are properly fortified with the vitamin. However, if you still want to be mindful of consuming food-sourced vitamin D, here are a few options.
- Beef liver (yuck), 1 microgram per 3 oz
- Eggs, 1.1 microgram per egg
- Fatty fish such as salmon, 11 micrograms per 3 oz
- Shitake mushrooms, 0.5 micrograms per 1/2 cup
- Fortified milk, cheese, cereal, juice, and bread, may contain 2.5 micrograms per cup (100 IU)
Vitamin D is a fat-soluble Vitamin which means it needs to bind with fat for it to be absorbed into your body. What does this mean for you? Cook or eat your eggs, fish, and shitake mushrooms in a fat such as oil. If you are using a supplement, eat a few almonds or some nut butter and then take your supplement.
How much Vitamin D do I need?
Male and Female – 600 IU (15 micrograms)
Adults 70+ years – 800 IU (20 micrograms) this is due to the skin aging and not being able to synthesize Vitamin D through the skin as efficiently as young skin
Is sun exposure or supplement use better?
Anytime your body can NATURALLY do something, always choose the NATURAL way when you are given the chance. Look at the sources of Vitamin D listed above and their Vitamin D content. It would take A LOT of food to reach your 600 IU daily allowance. That is assuming that all of it is absorbed which is not the case.
Fact – an estimated 50% of dietary vitamin D sources are absorbed. What this means is that if you ingest or take a supplement that is 500 IU, only about 250 IU will be absorbed in your body.
Fact – 15 to 30 minutes of sun exposure (think sleeveless shirt with shorts) produces 10,000 to 20,000 IU of Vitamin D.
Whoa, think about that. Your recommended daily allowance is 600 IU but in just 15 to 30 minutes you can get over 33 times that! The power of the human body, my friends! It is truly amazing. Now, of course this is all dependent on your skin tone and where you live. Individuals with darker skin tones with not synthesize as much Vitamin D via sun exposure as a fair-skinned individual. Also, there is clearly a difference in living in Wisconsin versus Arizona. Arizona is almost ALWAYS sunny, giving you no reason to not get natural Vitamin D (even when it’s 115 degrees out).
However, if you are going to supplement, make sure it is a QUALITY supplement from Nature Made which actually PAYS MONEY to have their product and claims investigated and verified. Seriously, they’re legit and what they advertise is what you get. Also, make sure your supplement is D3 and not D2. D3 is much more potent than D2.
What if I wear sunscreen?
I’m all for protecting your skin and I am personally a huge skin-health-freak. However, getting 15 to 30 minutes of sun exposure is not going to kill you. Wait 15 to 30 minutes and then put on your sunscreen. Avoid times when the sun is the strongest and maybe go on a morning walk with a tank, shorts, and sandals on.
Can I be Vitamin D deficient?
A number of factors can contribute to vitamin D deficiency. A few are being older in age, having liver or kidney diseases, alcohol consumption, bowel diseases or disorders, or inadequate consumption or exposure.
Rickets – vitamin D deficiency that prevents proper bone formation and growth. You’ve seen photos of children with bowed legs and enlarged wrists, ankles, and knees. This is unfortunately a vitamin D deficiency.
Osteomalacia – bone mineralization defect that is due to high levels of parathyroid hormone in the body. As you learned above, PTH is released when calcium levels are low. Pain and muscle weakness are common symptoms.
To sum it up:
- Spend 15 to 30 minutes outside in the sun for your daily Vitamin D dose
- If sun is not available, consume a supplement and vitamin D rich foods with a fat source (salmon, almonds, coconut oil)
- Advanced nutrition and human metabolism (this is one of my all-time FAVORITE nutrition books EVER!
Just in case you missed other micronutrient posts, check these out!