Vitamin D helps you absorb calcium from your food. Without it, your body would not have the calcium it needs to build strong bones.
I had a vitamin D deficiency many years ago, which came to light, not because of symptoms, but during the 25-hydroxyvitamin D lab test. My doctor advised me to spend time in the sun and take a vitamin D3 supplement. After following this advice for several years, I was tested again. The follow-up test indicated a Vitamin D overload. To bring the level down, my doctor recommended that I stop taking Vitamin D3 supplements for several months. The next time I was tested, my Vitamin D level was normal.
Today, I get vitamin D from the sun, food, and a low dose vitamin D3 supplement. To avoid excess or deficiency, I use the 25-hydroxyvitamin D blood test to monitor my levels.
What is Vitamin D?
Vitamin D is actually a hormone produced by the human body during exposure to sunlight. It supports absorption of three key minerals for bones: calcium, magnesium and phosphorous. The bone’s most important element is calcium, and Vitamin D must be present for calcium to be properly absorbed. It partners with vitamins A and K2 to direct calcium and other minerals into bones and teeth. Vitamin D is also critical for bone remodeling, a process by which old bone tissue is broken down and absorbed into the body, then replaced by new bone tissue.
Symptoms of vitamin D deficiency include osteoporosis/osteopenia (porous bones) and osteomalacia (bone softness). Vitamin D overload is usually caused by supplements as the body limits the amount it produces from sun exposure. Too much vitamin D can cause nausea, vomiting, poor appetite, constipation, weakness, and weight loss. Other symptoms of excess are confusion, disorientation, heart rhythm problems, and damage to the kidneys.
How much Vitamin D should you consume?
According to The National Academy of Medicine, the Recommended Dietary Allowance (RDA) is the amount needed to meet the nutritional needs of nearly all healthy people. For adult men and women, the RDA is 600 IU (15 micrograms) per day. If you are over 70 years old, the RDA is 800 IU (20 micrograms). Your dietary requirements are unique, depending on the amount of Vitamin D obtained from sunlight. During seasons of less sunlight, you may need more Vitamin D in your diet. Please consult your healthcare provider for advice on your particular needs.
Which foods are high in vitamin D?
Unfortunately, very few foods naturally contain vitamin D. Fatty fish have the highest levels. However, you can get smaller amounts from cheese, egg yolks, and some mushrooms. The amount can vary depending on how the animal or plant was raised. Most of the vitamin D in the American diet comes from fortified food. For more information, USDA FoodData Central has a searchable database at https://fdc.nal.usda.gov/fdc-app.html#/.
Recipes for vitamin D
Which vitamin D foods do you eat?
Let me know your favorites in the comments below – I’d love to hear from you.
For more information
Vitamin D Fact Sheet for Consumers
Dietary Reference Intakes for Calcium and Vitamin D, Institute of Medicine (IOM)
Now the National Academy of Medicine (NAM)