Ninety per cent of vitamin D is made from sunlight exposure directly on to the skin (not through glass). Only about 10 per cent of vitamin D comes from food sources such as oily fish, fortified milk and egg yolks.
If milk is fortified, it must contain 400 international units (IU) per quart. This amount meets recommended levels for children and younger adults. For older adults, who make less vitamin D in response to sunlight, the recommendation is 600 IU per day. These are tiny amounts.
Since each serving of milk only contains about 100 to 180 IU of vitamin D, you'll probably need additional food sources to meet the daily recommended 600-800 IU intake (Holick, 2011). Experts agree a varied diet rich in foods with vitamin D is the best way to ensure you're meeting the daily requirement.
Sunlight is the key: Its ultraviolet B (UVB) energy converts the precursor to vitamin D3. In contrast, most dietary supplements are manufactured by exposing a plant sterol to ultraviolet energy, thus producing vitamin D2.
Most commonly added vitamin D in milk is vitamin D3. Many categories of foods are permitted to include up to a specified amount of vitamin D.
The most common food fortified with vitamin D is fresh milk, contributing 44% of the total daily vitamin D intake.
A meta-analysis of randomized controlled trials that compared the effects of vitamin D2 and D3 supplements on blood levels found that D3 supplements tended to raise blood concentrations of the vitamin more and sustained those levels longer than D2. [76,77] Some experts cite vitamin D3 as the preferred form as it is ...
Good food sources of vitamin D include fatty fish such as salmon, especially the wild salmon, tuna, mackerel, mushrooms, eggs and vitamin D fortified foods such as milk (any milk will do--cow, soy, almond, or coconut milk are all fortified). My favorite way to get vitamin D in the winter is from salmon.
Oranges may be the closest you'll get to a fruit containing vitamin D.
Yogurt is a good source of probiotics, calcium, and proteins, but its content of vitamin D is low.
Therefore, conditions that affect the gut and digestion, like celiac disease, chronic pancreatitis, Crohn's disease, and cystic fibrosis, can reduce vitamin D absorption.
Fortified Milk Offers a Double Whammy: Vitamin D and Calcium
In addition to being an excellent source of calcium, 8 fluid ounces (fl oz) of fortified whole milk has 95.6 IU of vitamin D, per the USDA. According to the NIH, that added vitamin D improves calcium absorption.
Sunshine will raise levels of active Vitamin D within about 8 hours – depending on the strength of the sun and your level of absorption. Vitamin D3 supplements are thought to raise vitamin D levels in the bloodstream in around 24 hours.
If you're lacking in vitamin D, your skin may tell on you. For example, if you're not getting enough vitamin D, your complexion might be dull, lacking that desired glow and you might also experience dry, flaky skin on your face and other areas of your body.
Use the CVS Health At Home Vitamin D Test Kit to get accurate and comprehensive results in the privacy and comfort of your own home. Simply collect your blood sample using this convenient kit, mail it to the lab, and receive your results through a secure online portal in just a few days.
In summer and spring, with 22% of uncovered skin, 1000 IU vitamin D doses are synthesized in 10-15 min of sun exposure for adults.
Virtually all commercial and automobile glass blocks UVB rays. As a result, you will not be able to increase your vitamin D levels by sitting in front of a sunny window, though much of the UVA radiation will penetrate the glass and may be harmful.
Abstract. To get an optimal vitamin D supplement from the sun at a minimal risk of getting cutaneous malignant melanoma (CMM), the best time of sun exposure is noon.
"Adequate levels of magnesium in the body are essential for the absorption and metabolism not only of vitamin D but of calcium as well," Dean states. "Magnesium converts vitamin D into its active form so that it can help calcium absorption.
“Fish and seafood are major animal sources of vitamin D. The vitamin D present in them is better absorbed by the body, as compared to plant-based sources,” she suggests.
“Vitamin D3 cholecalciferol is the most absorbable and potent form, [whereas] Vitamin D2 (ergocalciferol) is typically plant-based and not as effective at raising vitamin D levels in the body and thus is not recommended as often,” she explains. When it comes to dosing, it can vary by individual, Bogden says.
The best food sources of vitamin D are oily fish, including salmon, mackerel, and sardines. Other sources include egg yolks, red meat, and liver. Vitamin D is added to some foods too, including breakfast cereals, plant milks and fat spreads.