Everything you need to know about Vitamin D
Or as John, Paul, George, and Ringo put it: Here comes the sun
What is vitamin D and what does it do?
Vitamin D is a nutrient found naturally in only very few foods. But vitamin D is different. Because unlike other nutrients, your body is able to produce vitamin D with the help of sunlight. So in a way, we're a little bit like plants, after all, just less green.
Your body needs vitamin D to absorb calcium. And calcium is one of the main ingredients of your bones. Your Muscles and nerves need vitamin D to function properly and it also helps to fight off infections and bacteria. Which is shown in this scientifically accurate drawing:
How much of it do I need?
Adults need 600 Units of vitamin D, which translates to 15 micrograms. Babies need 5 mcg less and the more experienced generation about 5 mcg more than that.
What foods contain vitamin D and how much of them do I need to eat per day?
There are several answers to this question. I bet this guy knows all of them.
Only very few foods naturally contain vitamin D. It's basically down to fatty fish such as swordfish and salmon. Most people get their vitamin D from other sources, though.
As mentioned before, your body can produce its own vitamin D. Medical research has shown that it takes about 5-30 minutes (depending on where you live) of direct sunlight twice a week to cover your body's demand for vitamin D.
HOWEVER, that's direct sunlight exposure of your arms, legs, face or back without sunscreen. Skin experts don't recommend to expose your body to direct sunlight for more than a couple of minutes without protection (clothing, sunscreen, etc.) due to the increased risk of developing skin cancer. Also, some of us live in countries that don't see the sun too often especially during the winter months (Norway, Sweden, Finland, ...). And then there's the UK with approximately 364 days of rain per year. Here is a picture of one of the rare sunny days in London:
Sorry, it took the photographer about 20 seconds to get his camera ready and of course it started raining again. Luckily, there are other sources of vitamin D.
The most common sources the majority of our vitamin D demand are fortified foods and drinks. Especially (plant) milk and juices are very often fortified with enough vitamin D to get you through the winter even if you spend most of your time indoors.
Of course, there are also dietary supplements for vitamin D. In fact, the American Academy of Pediatrics even recommends that breastfed infants should receive vitamin D supplements until they are weaned.
Surprised to hear about his demand for vitamin D
What happens if I don't get enough vitamin D?
Pain happens. Symptoms of vitamin D deficiency include bone pain and muscle weakness. Sounds trivial, but a severe deficiency can lead to very serious bone diseases. Especially vitamin D deficient children can suffer from rickets. Their soft bones will even bend and cause bowed legs, pain, and a large forehead.
Risk groups for vitamin D deficiency also include older adults, obese people and even folks with darker skin (because their ability to produce vitamin D from sunlight is lower).
Can an overdose of vitamin D also be harmful?
Yes. The upper intake level of vitamin D is 100 mcg (4000 units). A higher daily intake can lead to vitamin D poisoning. Initially, symptoms include nausea, constipation, weakness, and weight loss. Extremely high intake levels can even lead to kidney damage and heart problems.
Please note: Almost all cases of vitamin D poisoning come from overusing vitamin D supplements. Your skin won't produce more than your body needs from sun exposure. Love your skin. It's smart.
Does it have any other effects?
Yes. If you're on steroids for whatever reasons, you may want to cut down on vitamin D supplements because certain combinations will mess up your vitamin D metabolism. Please only take steroids if you have to for medical reasons. Be kind to your body.
Thanks for reading, I hope you liked it. I'll be back with more nutrition facts soon. Now go out and enjoy some sunshine!