Though I love the fatty fishes, not everyone does. That leaves supplementation in other foods from milk to margarine (sorry, not ice cream) and then supplements in pill form.
The recommended minimum daily intake is 600 IU/day; my doc has me on a regimen of over 7,000 IU per day. Supplements, especially at high doses, should not be taken unless a doctor recommends it based on results of a blood test.
Overdoses can occur, almost always from taking vitamin D in supplement form. Errors at the processing plant have led to cases of people getting too much in their milk or in supplements. Toxic levels can cause nausea, vomiting, dehydration, constipation, weakness, confusion, kidney damage, abnormal heart rhythm, calcium in abnormal parts of the body such as the blood vessels, and other ills.
We all have different needs for Vitamin D, depending on many lifestyle and other factors, and the only way to know how much we need and if we’re deficient is to get tested. Your personal physician can test you and prescribe supplements if you need them. Some of us are more at risk, if we choose to or have to avoid the sun, or if our diet is vegan, vegetarian or lactose intolerant. People with inflammatory bowel disease, who have had gastric bypass surgery, with cystic fibrosis or some kinds of liver disease, may be at increased risk for deficiencies as well.
Deficiency has been going up, perhaps due in part to fear of skin damage from the sun and increased obesity. So get your levels checked.
