What to use Nutrivital Vitamin D3 in Rice Bran Oil for? Despite being known as the sunshine vitamin, studies show that up to 50 per cent of Australians do not have adequate levels of Vitamin D. Vitamin D promotes the body's absorption of calcium which is important for maintaining healthy bones and teeth. Vitamin D deficiency is known to be more prvalent in the elderly and can result in muscle weakness, a possible contributor to falls in this age group. Vitamin D supplementation may improve strength, function and balance.