Why Does Vitamin D Matter?

02:59PM Mar 27, 2020
Chris Hoffman - PA
( National Pork Board and the Pork Checkoff )

When it comes to improving the performance and overall health of pigs, many producers think about feed additives or antimicrobials first, said Sara Hough, DVM, DSM, senior regional technical services swine-North America. 

“We need to get back to the basics,” Hough said during the American Association of Swine Veterinarians annual meeting on March 8 in Atlanta, Ga. “We need to take a closer look at the synergies between health and nutrition. Vitamins and minerals are a big part of that discussion.”

Why Vitamin D? 
Vitamin D has long been recognized as essential to the skeletal system for its necessary role for calcium and phosphorus metabolism. When pigs moved indoors, they lost their capability of absorbing vitamin D from UVB rays like humans can. Supplementing vitamin D in in the feed or water became necessary for calcium and phosphorus metabolism and to be able to have strong bones as well as increased muscle development, Hough said. 

Vitamins and minerals play a critical function in all stages of a pig’s life. Losing 30% of pigs from birth to market is a major industry concern now. Hough also encouraged producers to consider investing more thought into how this applies to the nutrition of the developing gilt.

“We need to consider ways to help improve the overall livability of all animals, including the developing gilt. If we want her to produce seven to nine litters before her lifetime is up, we need to invest in her more, and I think micronutrients are a part of that story,” Hough said. “We've come so far in genetics and producing animals that grow really fast and are expected to produce and lactate an abundance of offspring. I don't think we have fully considered how nutrition plays into that overall development,” she added.

In a Canadian study at Sherbrooke Research and Development Centre, Jacques Matte and his team recently explored alternative ways to provide supplements to piglets by feeding the supplements to sows in late gestation and during lactation.

Copper and vitamins A and D supplementation resulted in increased weight of the newborn piglets. The supplementation also reduced the weight difference between piglets in the same litter. At weaning, the composition of their microbiota improved, the release said. Piglets’ disease resistance and growth potential were also enhanced because of the weight gain and enhanced immunity stemming from more beneficial bacteria in the microbiota.

How does Vitamin D boost immune function?
Newer mounting evidence acknowledges vitamin D’s role in supporting immune function as well. 

“We’re learning there’s many other cellular functions that vitamin D is involved in, including pancreatic activity, various metabolic functions and immune function,” she said. “We’ve just started to scratch the surface on this.”

Vitamin D helps regulate normal immune function by encouraging the innate immune system to do what it's supposed to do, she said.

“It helps to hone-in and find the exposure pathogen and then assists the adaptive immune system to respond,” Hough explained. “It regulates that response so that it's not as detrimental as it could potentially be. As we know, particularly in autoimmune diseases, the way our body responds to foreign material can be overwhelming and do more harm than good. I think of vitamin D as a regulator that helps the immune system do its job while keeping within the restraints to not cause an overwhelming response. 

Why does it matter? 
Nearly 10 years ago, veterinarians started taking a deeper look at the role of vitamin supplementation due to increased issues in pigs post-weaning, Hough said. 

Since then, she’s seen renewed interest in vitamin levels and trying to interpret how those levels translate into the overall well-being of pigs, particularly nursery pigs. Hough said vitamin D helps dampen immunopathology while assisting with immunocompetence, which is critical during post-weaning stress and during gilt development. 

“We are trying to better understand this synergy between nutrition and health,” Hough said. “When you feel good enterically, you perform better, and your overall well-being is improved. The recognition of the importance of nutrition in the maintenance of immune functionality is likely to increase in significance as the swine industry continues to improve and produce a more efficient animal.”

More from Farm Journal’s PORK:
Can Micro-Supplements Improve Piglet Growth?

Vitamin D Supplementation Shows Positive Effect on Sows

Nutritional Diagnostics – Here Are 7 Tips