Thank you so much for your help. I thought vitamin D3 was added to most dairy products, so I assumed I was getting enough of it, but I guess not...
Take vitamin D3 and higher than 400IU. Upper Tolerable Limit for vitamin D is 4000IU. You may not need that much however. Magnesium is needed for vitamin D absorption. I found that out when I couldn't raise my vitamin D or calcium that magnesium is the boss! :)
"Very few foods in nature contain vitamin D. The flesh of fatty fish (such as salmon, tuna, and mackerel) and fish liver oils are among the best sources [1,11]. Small amounts of vitamin D are found in beef liver, cheese, and egg yolks." - NIH - Vitamin D.