Pregnancy and Vitamin D

Vitamin D is a fat-soluble vitamin, which means once it is absorbed it can be stored in the body’s fatty tissue. Our two main sources of vitamin D are derived from diet and UV rays in sunlight. Predominantly, the vitamin D absorbed through diet is vitamin D2 and the type derived through skin absorption from sunlight is vitamin D3. They perform the same function, the only difference being a slight variation in their chemical structures.

Vitamin D plays an important role in regulating the uptake and maintaining the necessary levels of calcium and phosphorous. Both calcium and phosphorous are required to ensure we have strong bones, teeth and muscle.

While biologically inactive itself, once vitamin D is absorbed, it undergoes a couple of changes – once via the liver and then via the kidney to convert it to its active form. The kidney uses parathyroid hormone to facilitate its part in the conversion.

Aside from the reduced UVB rays and exposure in winter months, pregnancy and breastfeeding can leave mothers further deficient in vitamin D. Mothers may also find it especially difficult to gain an adequate dietary intake too given many of the foods rich in vitamin D also need caution/limitation/avoidance during pregnancy. Therefore,  the NHS encourage that pregnant and breastfeeding women should supplement with daily vitamin D.

Doses of Vitamin D

The recommended supplementary dose for pregnant and breastfeeding mothers as per the NHS is 400 units or 10 micrograms once daily throughout these periods.

This strength of vitamin is typically available from your local pharmacy, with branded versions commanding a higher retail price than generic versions. As long as the dosage strength is the same, they do the same job.

You may also see units expressed as “iu” and micrograms expressed as “mcg or µcg” on the labels. If you’re not sure, always ask.