Vitamin D is either ingested from food or synthesized in the skin during sun exposure, that is why Vitamin D is also described as the “sunshine vitamin,”. For most people, sun exposure is the primary determinant of vitamin D status, accounting for 80–90% of the vitamin D the body stores. But cloudy days, the low light of winter, and the use of sun block (important to avoid skin cancer and skin aging) all interfere with sunlight absorption.
Although Vitamin D is best known for supporting a healthy bone structure, given its vital role in calcium absorption, the body transforms a form of the vitamin D – D3 or Cholecalciferol – into a hormone that is believed to improve Muscle Function, the Immune System, Mood, and Brain Health.
Unfortunately, vitamin D deficiencies are becoming more and more common, in part because we are spending more time indoors and using more sunscreen.
Experts say it’s better to rely on food and supplements
Vitamin D is a fat-soluble vitamin that is naturally present in very few foods, added to others, and available as a dietary supplement.
Some of the foods that are among the best sources of vitamin D are: the flesh of fatty fish (such as salmon, tuna, and mackerel) and fish liver oils
Cod liver oil, 1 tablespoon
Swordfish, cooked, 3 ounces
Salmon (sockeye), cooked, 3 ounces
Tuna fish, canned in water, drained, 3 ounces
Fortified Orange juice, 1 cup (average varies)
Fortified Milk (nonfat, reduced fat, whole), 1 cup
Yogurt, fortified with 20% of the DV for vitamin D, 6 ounces
Margarine, fortified, 1 tablespoon
Sardines, canned in oil, drained, 2 sardines
Liver, beef, cooked, 3 ounces
Egg, 1 large (vitamin D is found in yolk)
Fortified cereal with 10% of the DV for vitamin D, 0.75-1 cup
Cheese, Swiss, 1 ounce
Vitamin D is among one of the most sought after Dietary Supplements. There is no gain by taking a vitamin D supplement several times daily over taking one capsule once a day. But a vitamin D supplement is best absorbed when taken with food containing fat, and that’s the largest meal of the day for most people. A study at the Cleveland Clinic showed that if you take your vitamin D with the biggest meal each day, you can increase the level of vitamin D in the blood by an average of 50 percent.
According to the National Institutes of Health (NIH), the daily Adequate Intake (AI) for adults is 5 mcg (200 IU) daily for males, female, and pregnant/lactating women under the age of 50. People older than 50 years should get 10 mcg daily (400 IU) daily, and those over 70 should get 15 mcg daily (600 IU).
Recent research, though, recommends up to 50 mcg or 2,000 IU of vitamin D per day. Anyhow, the approach for anyone with vitamin D deficiencies, should be to discuss proper intake levels with his or her physician.