For anyone who has concerns about getting adequate vitamin D from their diet and/or time outdoors, Manson said that supplementation with 1000 to 2000 IU/day of vitamin D would be “very reasonable.”
“More is not necessarily better, and very high doses—such as more than 10,000 IU/day—may be associated with high blood or urine calcium levels and toxicity.”
— Dr. JoAnn Manson
Good Sources of Vitamin D
| Food Source | Vitamin D Content |
|---|---|
| Fatty fish (salmon, sardines, tuna) | High |
| Wild mushrooms | Moderate to high (depending on sun exposure) |
| Fortified dairy products | Varies (check labels) |
| Fortified cereals | Varies (check labels) |
| Fortified orange juice | Varies (check labels) |
Pro tip: “In the U.S., foods such as dairy products, cereal, and orange juice are often fortified with vitamin D, so checking nutrition labels can help you make better decisions about which foods to purchase,” Manson advised.
Sun Exposure
Going out for a 15-minute walk a few times a week at midday will typically provide enough sunlight exposure for the skin to synthesize vitamin D, Manson added.
“Even more important for your health would be to exercise outdoors, such as brisk walking, jogging, or playing sports.”
— Dr. JoAnn Manson
Who Is at Higher Risk of Vitamin D Deficiency?
| High-Risk Group | Reason |
|---|---|
| Living in nursing homes | Limited sun exposure |
| Malabsorption conditions (Crohn’s, celiac disease) | Impaired absorption |
| Osteoporosis or other bone health problems | Increased need |
| Major dietary restrictions (severe lactose intolerance) | Limited dietary sources |
Recommendation: “[People in these groups] should talk with their doctors about being tested for vitamin D blood levels and taking a vitamin D supplement,” Manson recommended.
