The great thing about Vitamin D is that it is free and readily available most times of the year, in most places via natural sunlight. Just 10 minutes a day of direct sunlight, 3 times a week, or 20 minutes of direct sunlight, once a week, provides a baby and child's body with all the Vit D necessary. It is more easily and readily used (and more natural) than pill-form supplements.
This statement highlights the fact that as long as Mom has all the Vit D she needs, her baby gets plenty from her milk. No additional supplements are needed. It is the perfect feeding design! So get out and enjoy a little sunlight now and then...and let your baby do the same on occasion as well.
It should be noted that it is best to not wash all your skin (or baby's) with soap too often - Vit D needs to absorb via the skin and daily scrubs interfere with this. Many doctors specializing in immunity and nutrition recommend a "pits and bits" soap wash for adults and occasionally for baby (as well as hands, of course). All over daily washes are not needed, and may actually deter from health and natural immunity building.
According to the Vitamin D Council:
The single most important fact anyone needs to know about vitamin D is how much nature supplies if we behave naturally, i.e., go into the sun. Humans make at least 10,000 units of vitamin D within 30 minutes of full body exposure to the sun.
Fear of the fatal form of skin cancer, malignant melanoma, keeps many people out of the sun. The problem with the theory is that the incidence of melanoma continues to increase dramatically although many people have been completely avoiding the sun for years. We are not saying sunburns are safe, they are not. We are saying that brief, full-body sun exposure is a much smarter thing to do than suffering from vitamin D deficiency.
For more info on the topic:
An article on safe sun exposure (pdf)
Physician and lactation expert, Dr. Jack Newman's, information on breastfeeding and vitamins.
Book: The Healing Sun: Sunlight and Health in the 21st Century
Pregnant women not getting enough Vit D (it is best to take prenatal vitamins for 3 months prior to conception, during pregnancy, and after for the duration of time you are breastfeeding)
La Leche League International encourages all mothers to recognize the importance of vitamin D to the health of their children. Recent research shows that due to current lifestyles, breastfeeding mothers may not have enough vitamin D in their own bodies to pass to their infants through breastmilk.
In October 2008, the American Academy of Pediatrics recommended that infants receive 400 IU a day of vitamin D, beginning in the first few days of life. Children who do not receive enough vitamin D are at risk for rickets and increased risk for infections, autoimmune diseases, cancer, diabetes, and osteoporosis.
Vitamin D is mainly acquired through exposure to sunlight and secondarily through food. Research shows that the adoption of indoor lifestyles and the use of sunscreen have seriously depleted vitamin D in most women. The ability to acquire adequate amounts of vitamin D through sunlight depends on skin color and geographic location.
Dark-skinned people can require up to six times the amount of sunlight as light-skinned people. People living near the equator can obtain vitamin D for 12 months of the year while those living in northern and southern climates may only absorb vitamin D for six or fewer months of the year.
For many years, La Leche League International has offered the research-based recommendation that exclusively breastfed babies received all the vitamin D necessary through mother’s milk. Health care professionals now have a better understanding of the function of vitamin D and the amounts required, and the newest research shows this is only true when mothers themselves have enough vitamin D. Statistics indicate that a large percentage of women do not have adequate amounts of vitamin D in their bodies.
La Leche League International acknowledges that breastfeeding mothers who have adequate amounts of vitamin D in their bodies can successfully provide enough vitamin D to their children through breastmilk. It is recommended that pregnant and nursing mothers obtain adequate vitamin D or supplement as necessary. Health care providers may recommend that women who are unsure of their vitamin D status undergo a simple blood test before choosing not to supplement.
Parents or health care providers who want more information on rickets, vitamin D in human milk, or other information on breastfeeding issues visit: La Leche League International