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Fat-soluble Vitamins go thru the slow lymph system

Some Vitamin D in gut goes thru the lymph system (radioactive tracing) - May 1984

Lymphatic absorption and transport of retinol and vitamin D-3 from rat intestine. Evidence for different pathways
Biochim Biophys Acta. 1984 May 16;772(2):109-16. doi: 10.1016/0005-2736(84)90033-6.
R Blomhoff, P Helgerud, S Dueland, T Berg, J I Pedersen, K R Norum, C A Drevon

The lymphatic absorption and transport of retinol and vitamin D-3 from rat intestine has been studied. When rats were cannulated in the intestinal lymph duct and given an intraduodenal bolus of [3H]retinol and 14C-labelled vitamin D-3, 14C-labeled vitamin D-3 appeared later in the intestinal lymph than [3H]retinol and the rate of absorption of vitamin D-3 was still maximal at a time when that of retinol had declined. Both vitamins were absorbed via the lymphatic route in association with chylomicrons. Almost all the retinol was esterified, while vitamin D-3 appeared in the chylomicrons as free vitamin D-3. In vitro incubations and in vivo studies using hepatectomized and normal rats showed that the retinyl ester was a relatively nonexchangeable component of the chylomicrons and their remnants. Hence, all the vitamin A followed the remnants in their clearance from plasma.
In contrast, significant amounts of vitamin D-3 were transferred from the chylomicrons to other plasma fractions.
Therefore, only a fraction of this vitamin may be removed in association with the chylomicron remnants.
 Download the PDF from VitaminDWiki

Perplexity AI April 2024:

Question: Vitamin D in the gut is thought to go into the blood. Some people believe that the vitamin D has to go thru the lymph system before getting into the blood. Which is correct?

AnswerVitamin D is absorbed through both the lymphatic system and directly into the bloodstream, depending on its form and the circumstances of absorption. The primary pathway for the absorption of vitamin D (specifically vitamin D3) involves its incorporation into chylomicrons, which are lipoprotein particles formed in the enterocytes (intestinal cells). These chylomicrons, containing vitamin D, are then secreted into the lymphatic system, bypassing the portal circulation initially. From the lymphatics, they eventually enter the bloodstream, where vitamin D can be transported to various tissues, including the liver for further metabolism

.However, it's also been shown that certain metabolites of vitamin D, such as 25-hydroxyvitamin D3, can be absorbed directly into the portal blood, independent of fat absorption and the lymphatic system

This suggests that there are differential pathways for the absorption of vitamin D and its metabolites, with some forms entering the bloodstream directly and others being transported via the lymphatic system.In summary, both beliefs are correct in that vitamin D can enter the bloodstream both directly and through the lymphatic system, depending on the form of vitamin D and the metabolic processes involved.

Follow-on question: What is the role of chylomicrons in vitamin d absorption
Chylomicrons play a crucial role in the absorption and transport of vitamin D. After vitamin D is ingested, it is absorbed in the small intestine, where it is incorporated into chylomicrons, which are lipoprotein particles formed within the enterocytes (intestinal cells). These chylomicrons are then secreted into the lymphatic capillaries, effectively bypassing the hepatic portal circulation during their initial phase of transport.

The chylomicrons, containing vitamin D along with other dietary lipids, travel through the lymphatic system and eventually enter the bloodstream. Once in the systemic circulation, the chylomicron lipids are metabolized in peripheral tissues, particularly in adipose tissue and skeletal muscle, which are rich in the enzyme lipoprotein lipase. During the hydrolysis of the chylomicron triglycerides, a fraction of the vitamin D contained within the chylomicron can be taken up by these tissues.

This process accounts for the rapid postprandial disappearance of vitamin D from plasma, as it is taken up by tissues or stored. What remains of the original chylomicron after lipolysis is a chylomicron remnant, which still contains a fraction of its vitamin D content. These remnants are then cleared from the circulation by the liver, where vitamin D can be further metabolized to its active forms.

In summary, chylomicrons are essential for the absorption and initial transport of vitamin D from the intestine to the bloodstream and peripheral tissues, where it can be utilized or stored.

References, images, videos, etc

Summary: Fat soluable Vitamin D (cholecalciferol) goes thru slow lymph system

Since the lymph system does not have a pump, you might speed up the response to oral vitamin D by walking/movement
Path: gut ==> lymph system ==> thoracic duct ==> blood

Semi-activated Vitamin D (Calcifediol) and perhaps water-soluable and emulsion forms, quickly get into bloodstream

Suspect: Both sublingual and emulsion forms of the vitamins get into the blood stream much faster

Asked Gemni AI: Which of the fat-soluable vitamins go thru the lymph system before getting to the blood? (April 2024)

  • The fat-soluble vitamins that primarily go through the lymph system before entering the bloodstream are: A. D, E, K
  • Solubility: Fat-soluble vitamins need fat to be absorbed. Bile in the digestive system helps break down fats and makes these vitamins available for absorption.
  • Packaging: These vitamins, along with fats, are packaged into particles called chylomicrons.
  • Transport: Chylomicrons are too large to enter the bloodstream directly, so they enter the lymphatic vessels in the intestines. The lymphatic system carries them and eventually empties them into the bloodstream.

Vitamin D from the skin enters the blood quickly, bypassing the lymphatic system

Skin sources of Vitamin D:Sun, UV, topical, sublingual

VitaminDwiki – Getting Vitamin D into your body has a chart


The TOP articles in Forms of Vitamin D (including Calcitriol, Calcidiol, and Injection):

Attached files

ID Name Comment Uploaded Size Downloads
21076 Lymph rats_CompressPdf.pdf admin 09 Apr, 2024 300.72 Kb 13
21074 Lymph system.png admin 09 Apr, 2024 205.60 Kb 61