- Foodwise, the richest sources of vitamin D are egg yolks, fish liver oil, some types of fish, butter, liver and cheese, according to HealthVitaminsGuide.com. Mushrooms also include some vitamin D as does the flesh of mackerel, salmon and tuna, according to the National Institutes of Health.
- Most foods are not rich in vitamin D so you will probably need to take a multivitamin as well as get reasonable exposure to the sun. According to William Davis, M.D., the amount of vitamin D must be individualized and depends on body size, fat content, age and race. For women, he recommends 4,000 to 5,000 units per day; the dosage for the average man is 6,000 units per day. Dr. Davis notes that there are exceptions: Sometimes a small woman will require more vitamin D than a large man, and a young person may need a lot more than a middle-aged male or female. Your blood level must be measured before this determination can be made. The proper dosage would raise your vitamin D levels to 60 to 70 ng/ml.
- In the United States milk, calcium-fortified fruit drinks and juices, and cereal flours are among foods that processors fortify with vitamin D.
- If you are housebound or live in a climate where there is little sunshine, you may be at risk for developing a vitamin D deficiency. Vitamin D is needed to ensure healthy bone growth and development. In children, lack of this nutrient can result in rickets; in adults, a D deficiency can cause muscle and bone weakness.
- Especially at risk for developing a vitamin D deficiency are women who are dark-skinned. If your skin is dark, your body produces greater amounts of sun-protective pigmentation (melanin). The darker the skin, the less able it is to produce vitamin D from sun exposure.
- Breastfed infants are at risk for developing a vitamin D deficiency because breast milk alone does not provide adequate amounts of vitamin D, especially if the nursing mother has low levels to begin with. Because parents are encouraged to keep their infants out of the sun, your baby cannot reap the D benefits of sun exposure. Consult with your physician about supplementation for your infant.
- Regular use of laxatives can deplete your supply of D, according to the National Institutes of Health, and mineral oil reduces its absorption. Some drugs and herbs can interact with vitamin D or interfere with its absorption. If you take steroids, cholesterol-lowering drugs, osteoporosis medication or other drugs or herbs, consult your physician before supplementing with vitamin D.
- Dr. Davis points out that vitamin D--which he says is not a true vitamin--is the only hormone that is not obtained through diet but is created by the skin in response to sun exposure. Our ability to activate vitamin D diminishes by age 40. The National Institutes of Health notes that from 5 to 30 minutes of sun exposure between 10 a.m. and 3 p.m. twice a week without sunscreen should be sufficient exposure for vitamin D synthesis.
