Vitamin D
Lactation Celebration Month Part 6: Vitamin D.
This is not medical advice on how much vitamin D you should take. Please discuss your health needs with your primary care provider. This blog is for informational purposes only, though I hope to empower you to ask your provider questions when blanket Vitamin D recommendations don’t seem to fit your needs.
What is it?
Vitamin D3 (cholecalciferol) is a hormone produced by our bodies when exposed to UVB light. Vitamin D helps our bodies absorb and utilize calcium and phosphorous. Proper amounts calcium and phosphorous in our bones and prevents a disease called rickets in children or osteomalacia and osteoporosis in adults.
Calcium is necessary to preserve a working nervous system, promotes bone growth, and maintains bone density. Phosphorous helps build teeth and bones, and is necessary for our cells to function. It activates enzymes, helps regulate our DNA and RNA, and is important for intracellular energy storage.
Vitamin D also plays an important role in disease prevention by inhibiting inflammatory responses in the body. Vitamin D promotes bone integrity, plays a role in cancer prevention, decreases the incidence of autoimmune disease (Type 1 diabetes, multiple sclerosis, rheumatoid arthritis, lupus (SLE)), protects against cardiovascular disease and neurodegenerative disease (Alzheimer’s, Parkinson’s), promotes healthy fetal growth, protects against acute respiratory infections, and may play a key role in Covid-19.
Why do we need it?
Because we’re (hopefully) doing a great job protecting our skin from the harmful effects of UV radiation from the sun.
UVB light from the sun is what helps our bodies make Vitamin D, we need at least 10 min of direct sunlight in order to create a normal level of vitamin D. Except in the summer, anyone living north of 37 degrees latitude is at significant risk of vitamin D deficiency for most of the year. Now, the only reason I know I’m above 37 deg latitude is because I’ve crossed the 45th parallel many times as an Oregonian. Thanks, I5, for that sign! In the USA, that’s about anything north of San Francisco.
This is info from Harvard, which is in the northern hemisphere. I assume the recommendation is similar for those living the south of the same latitude in the southern hemisphere. But, I’m no sun expert.
However, anyone who’s wearing UVA and UVB blocking sunscreen or clothing (good job protecting your skin!) is not going to get UVB exposure in order to produce adequate vitamin D levels. There are also other factors like weather, buildings blocking direct sun, air pollution…a whole host of things that affect one’s ability to get enough UVB exposure.
If we are able to have enough sun exposure, we would not need vitamin D supplements. 10 min is a minimum and people with darker skin need longer exposure due to melanin’s natural UVB absorption. Melanin competes with 7-dehydrocholesterol which eventually turns into Vitamin D3.
Adequate UVB rays to the skin naturally produces 10,000-25,000 International Units (iu) of vitamin D. You cannot overdose on vitamin D absorbed from the sun.
Because it’s difficult to practice skin cancer prevention and also get adequate sun exposure, taking a supplement is a simple solution.
How much vitamin d should i take?
Ask your doctor! Everyone’s health needs vary and finding the right amount for your body is best done with the help of someone who knows your whole health history. I am not providing medical advice!
In late July, daily recommended value on food labels for a non-pregnant, non-lactating adult increased from 400iu/day to 800iu/day.
Studies (see below) show that if you are lactating, you should take at 6000iu/day + the 400iu in a multivitamin in order to give your baby an adequate amount of vitamin D via your milk.
However, if you are vitamin D deficient, you need more than the recommended dose. The dose is also increased based on your body type and certain medications. Some people need to take 2-3 times the recommended dose but for some people this may not be necessary. So it really is best to discuss your needs with your primary healthcare provider.
Do need to give my baby Vitamin D?
Yes, maybe. It depends on how much vitamin D3 you take. Because most people are deficient in Vitamin D, milk levels are typically low. If you have your vitamin D levels checked, they are not actually checking vitamin D. They look for the active form of vitamin D called 25-hydroxyvitamin D (aka 25(OH)D). This active form of vit D is not the form that passes through human milk.
In order to know if your milk has sufficient levels vitamin D, you’d need to do a blood test to measure your baby’s 25(OH)D levels.
In a 2015 study by Dr. Bruce Hollis, PhD, parent and infant blood levels of 25(OH)D were monitored in 3 groups.
Group 1: baby receives vitamin D 400iu/day; parent took 400iu/day in a prenatal vitamin (PNV)
Group 2: Baby had nothing; Parent took 2000iu/day + 400iu/day in PNV = 2400iu
This group was eventually stopped due to safety concerns for the infant
Group 3: Baby had nothing; Parent took 6000iu/day + 400iu/day in PNV = 6400iu
The researchers found that a parent taking 6400 iu/day for 6 months, bumped the baby’s vitamin D levels up to the equivalent of 700iu/day*, thus making human milk a stand alone source of adequate vitamin D.
If a parent cannot regularly take 64000 iu of vitamin D, it is recommended to supplement your baby with at least 400iu/day if vitamin D3.
If your baby is receiving exclusive formula feeding, supplementing with 400iu is still recommended because in order to get a full 400iu from formula (all formula has vitamin D added to it), a baby would need to be eating at least 32oz of formula per day. A small baby may only be eating 1/2-3/4 that amount.
*This number came from Dr. Bruce Hollis in a webinar on vitamin D from USLCA in early April that I watched. Unfortunately this was a live webinar only and is no longer available. But I took some awesome notes.